Patent Publication Number: US-2015062789-A1

Title: Server adapter

Description:
BACKGROUND 
     Server systems generally include a chassis having an interconnecting circuit board, such as a backplane or a mid-plane, that connects one or more server circuit boards to other server system components such as hard drives, power supplies and the like. The chassis is frequently limited for use with only those server circuit boards which are specifically designed to work with the particular interconnecting circuit board. Modifying the interconnecting circuit board to interface with a new type of server board is often expensive and sometimes impossible. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic illustration of an example server system. 
         FIG. 2  is a schematic illustration of an example adapter of the server system of  FIG. 1 . 
         FIG. 3  is a schematic illustration of another example adapter of the server system of  FIG. 1 . 
         FIG. 4  is a schematic illustration of an example input-output module for the server system of  FIG. 1 . 
         FIG. 5  is a flow diagram of an example method that may be carried out by the server system of  FIG. 1 . 
         FIG. 6  is a flow diagram of another example method that may be carried out by the server system of  FIG. 1 . 
         FIG. 7  is a flow diagram of another method that may be carried out by the server system of  FIG. 1 . 
         FIG. 8  is a perspective view of an example implementation of the server system of  FIG. 1 . 
         FIG. 9  is a perspective view of the server system of  FIG. 8  with portions omitted for purposes of illustration. 
         FIG. 10  is a top view of the server system of  FIG. 9 . 
         FIG. 11  is another perspective view of the server system of  FIG. 8  with portions omitted for purposes of illustration. 
         FIG. 12  is a rear elevational view of the server system of  FIG. 8 . 
         FIG. 13  is a perspective view of an example adapter of the server system of  FIG. 8 . 
         FIG. 14  is a top view of the adapter of  FIG. 13  and an example server board for the server system of  FIG. 8 . 
         FIG. 15  is a top view of the adapter and the server board of  FIG. 14  connected to one another. 
         FIG. 16  is a front view of the connected adapter and server board of  FIG. 15 . 
         FIG. 17  is a schematic illustration of the adapter of  FIG. 13 . 
         FIG. 18  is a schematic illustration of an example input-output module of the server system of  FIG. 8 . 
         FIG. 19  is a rear perspective view of the input-output module of  FIG. 18 . 
         FIG. 20  of the top view of the input-output module of  FIG. 18 . 
         FIG. 21  is a rear perspective view of the server system of  FIG. 8  with some portions omitted for purposes of illustration. 
         FIG. 22  is a top view of an example adapter card and option card connected to an input-output module of the server system of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS 
       FIG. 1  schematically illustrates an example server system  20 . Server system  20  facilitates use of different server circuit boards with a single chassis or interconnecting circuit board. Server system  20  further facilitates the exchange or replacement of one server circuit board in the server system with a different server circuit board having a different interface. As will be described hereafter, server system  20  utilizes an adapter circuit board to interface between a server circuit board and an interconnecting circuit board. 
     Server system  20  comprises enclosure  24 , mid-plane  26 , memory device backplane  28 , internal memory devices  30 , server circuit board  32 , server adapter  34 , input-output module  36  and modular control auxiliary or daughter cards  38 ,  40 . Enclosure  24  and mid-plane  26  form chassis  42  for receiving and being connected to the remaining components of server system  20 . Enclosure  24  comprises an outer casing, housing and the like which encloses and supports mid-plane  26  as well as the other components of server system  20 . Mid-plane  26  comprises a circuit board including electrically conductive traces and electronic components by which power and data signals are transmitted or routed between those components connected to mid-plane  26 . Although illustrated as including mid-plane  26 , in other implementations with other architectures or layouts, server system  20  may alternatively use a backplane or other circuit board for interconnecting components of server system  20 . 
     Memory device backplane  28  comprises a circuit board upon which internal memory devices  30  are removably mounted for use by server system  20 . Memory device backplane  28  includes electrical traces and electronic components to connect such internal memory devices to mid-plane  26  and facilitates multiplexing of data or communication to and from each of internal memory devices  30 . Memory device backplane  28  includes connectors  44  and  46 . Connectors  44  are supported or mounted to backplane  28  and facilitate connection of internal memory devices  30  to backplane  28 . Connector  46  comprises a connector, such as an electronic plug, extending from backplane  28  to connect to a corresponding connector or port of mid-plane  26 . Although illustrated as comprising a single memory device backplane, in other implementations, server system  20  may include multiple memory device memory device backplanes. Although schematically illustrated as supporting two internal memory devices  30 , in most other implementations, memory device memory device backplane  28  may support well more than two internal memory devices  30 . 
     Internal memory devices  30  comprise devices for storing and retrieving digital information, such as computer data, that are releasably mounted or connected to memory device backplane  28 . Internal memory devices  30  comprise one or more of nonvolatile, random access, magnetic, digital or data storage devices. In one implementation, internal memory devices  30  comprise hard disk drives or disk drives, rigid or hard rotating discs or platters coated with magnetic material, wherein magnetic head is read and write data to such surfaces. In another implementation, internal memory devices  30  may comprise other non-transient computer-readable mediums, such as solid state memory devices. In some implementations, internal memory devices  30  may be fixed to memory device backplane  28 . 
     Server circuit board  32 , also referred as a server board, comprises a circuit board supporting server components for use by server system  20 . Server circuit board  32  carries server or blade components such as processors, connectors, server-storage array controllers, ethernet controllers, dual in-line memory devices (DIMMs), switches, routers, gateways and input-output interfaces or ports. Server circuit board  32  along with the server blade components (processors, memory and the like) form a server or node. As will be described hereafter, in some implementations, some components of server board  32  may be omitted where such components are now provided by adapter circuit board  34 , input-output module  36  and/or modular control daughter cards  38 ,  40 . Server circuit board  32 , and its components, facilitate the use of server system  20  to host one or more services or computational tasks on behalf of clients. Depending upon the type of services provided by the server formed by server circuit board  32 , server system  20  may comprise an application server, a catalog server, the communication server, a fax server, a database server, a file server, a game server, a name server, a print server, a proxy server, a sound server, a web server and the like. 
     As schematically shown by  FIG. 1 , server circuit board  32  comprises a bus slot  50  and a connector  52 . Bus slot  50  comprises an input-output interface to in the form of a slot to receive a card or riser. In one implementation, bus slot  50  comprises a peripheral component interconnect express PCIe bus slot. In other implementations, bus slot  50  may utilize other present or future developed bus or interface configurations. In other implementations, the server circuit board  32  may have  2  or more bus slots  50  that connect to the server adapter  34 . 
     Connector  52  comprises an interface to facilitate releasable or removal connection of server circuit board  32  to mid-plane  26  or another interconnecting board (such as a backplane) for the supply of power and the communication of data to and from server circuit board  32  and its components. In the example illustrated, connector  52  may or may not be specifically configured to mate with a corresponding connector or connection portion of mid-plane  26 . In the example illustrated, connector  52  is not utilized as connection with mid-plane  26  is facilitated by adapter  34 . In some implementations, connector  52  may be omitted. 
     Adapter  34  comprises a custom interface between server circuit board  32  and an interconnect circuit board, such as mid-plane  26 .  FIG. 2  schematically illustrates adapter  34  distinct from system  20 . Adapter  34  may be provided as part of system  20  or may be provided separately from system  20  after prior acquisition of system  20  to facilitate use of different server circuit boards, such as server circuit board  32 ′having a differently configured connector interface  52 ′. 
     As shown by  FIG. 2 , adapter  34  comprises adapter circuit board  56 , riser  58  and connector  66 . Adapter circuit board  56  comprises a printed circuit board carrying and supporting riser  58  and connector  66  while including electrical traces (such as the one electrical trace  68  schematically shown in  FIG. 2 ) electrically connecting riser  58  and connector  66  to one another and to other electrical components that may be carried by adapter circuit board  56 . 
     Riser  58  comprises a printed circuit board or card projecting from adapter circuit board  56  which includes an edge connector having electrical contacts or connections for being received within bus slot  50  of server circuit board  32 . Riser  58  includes electrical traces for distributing and routing data and power signals from bus slot  50  of server circuit board  32  to adapter circuit board  56 . In one implementation, riser  58  comprises a PCIe card. In one implementation, riser  58  has an edge opposite to the edge connector that is permanently fixed or attached to adapter circuit board  56 . In another implementation, adapter circuit board  56  may itself include a bus slot, wherein riser  58  has two edge connectors, with one of the edge connectors position in the bus slot of the adapter circuit board  56  and the other of the edge connectors receivable within bus slot  50  of server circuit board  32 . Riser  58  facilitates connection of adapter circuit board  56  to server circuit board  32  using an existing bus slot  50  on server circuit board  32 . Riser  58  facilitates the use of adapter  34  with a variety of different server circuit boards. 
     In one implementation, riser  58  comprises a card extending perpendicular to adapter circuit board  56 . In another implementation, riser  58  comprises a card extending parallel to but spaced from adapter circuit board  56 . In the example illustrated, adapter  34  is illustrated as including a single riser  58  for use with a server circuit board developed to use an Advance Micro Devices (AMD) processor architecture. However, in other implementations, adapter  34  may include a plurality of risers  58 . For example, adapter  34  may include a pair of risers  58  for being simultaneously received within a pair of bus slot  50  where the circuit board  32  has an INTEL processor architecture. 
     Connector  66  comprises an interface for connecting adapter  34 , and in particular, adapter circuit board  56 , to an interconnecting circuit board, such as mid-plane  26 . Connector  66  mates and connects with a corresponding connector portion of mid-plane  26 . In one implementation, connector  66  is configured so as to connect to mid-plane  26  using the same connecting portion of mid-plane  26  that would otherwise be connected to an interface or connector of a server circuit board  32 . In other implementations, connector  66  may be configured to be connected to other connectors of mid-plane  26 . 
     As shown by  FIG. 1 , adapter  34  interfaces between server circuit board  32  and mid-plane  26 . As a result, server circuit board  32  may be utilized in server system  20  even in those circumstances where connector  52  of server circuit board  32  is not configured for connecting with a particular connection architecture or connector of mid-plane  26 . Moreover, as indicated by arrows  70 , adapter  34  facilitates the replacement of server circuit board  32  with a different server circuit board  32 ′having a different connector  52 ′. As a result, server circuit board  32  may be replaced with an updated or more technically advanced server circuit board  32  while continuing use of many, if not all, of the other components of server system  20 . In addition to facilitating easier exchange or replacement or server circuit board  32 , adapter  34  facilitates mixing of various types of server boards to a single mid-plane  26  in a single server system  20 . 
       FIG. 3  schematically illustrates adapter  74 , an example of another adapter that may be utilized in place of adapter  34  in server system  20 . Adapter  74  is similar to adapter  34  except that adapter  74  additionally includes repeaters  76 . Repeaters  76  (also sometimes referred to as re-drivers) comprise electronic circuit chips carried by adapter circuit board  56  which receive signals that are received by riser  58  and re-drive such signals such that signals are passed on to connector  66 . Repeaters  76  repeat signals to preserve signal integrity over large transmission distances. Repeaters  76  preserve signal integrity despite the longer signal transmission distances resulting from the use of adapter  74  where such signals are transmitted across riser  58  and across adapter circuit board  56  prior to reaching mid-plane  26 . 
     In one implementation, repeaters  76  comprise a PCIe driver. In one example, repeaters  76  each comprise a low-power, four-lane repeater with four stage input equalization and output de-emphasis driver, referred to as a 6 DS80PCI800 and commercially available from TEXAS INSTRUMENTS. In one implementation, adapter  74  comprises 6 6 DS80PCI800 chips, accommodating 24 PCIe communication lanes in both directions. Each lane is composed of a transmit and receive pair of differential lines composed of four wires or signal paths to provide a full-duplex byte stream in both directions simultaneously. In other implementations, adapter  74  may comprise a greater or fewer of such repeaters  76 , accommodating a different number of communication lanes. In other implementations, adapter  34  may include repeaters  76  having other configurations, accommodating a same or a different number of such communication lanes. 
     In one implementation, adapter  74  additionally includes one or more reference clock buffers  77  for re-driving a reference clock. In one implementation, such buffers may comprise three zero-delay buffer supports commercially available under the identification ICS9DB102. Each buffer  77  is driven by a differential SRC output pair from an ICS CK410/CK505-compliant main clock to attenuate jitter on an input clock to maximize performance. In one implementation, adapter  74  comprises three of such chips. In other implementations, adapter  74  may omit such clock buffers or may utilize other clock buffers or repeaters. 
     Input-output module  36  comprises a device that facilitates modularity and adaptability of inputs and outputs for server system  20 . Input-output module  36  facilitates the exchange, service or upgrade of server circuit board  32  by relocating input-output interfaces and controllers for server circuit board  32  onto a separately mounted structure such that the server circuit board  32  may be exchanged, serviced or upgraded with fewer, if any, changes to the input-output architecture or layout including the associated cabling. In other words, server circuit board  32  may be upgraded, repaired or redeployed with reduced disturbance to an existing external cabling system without a loss of input-output, such as a storage array (i.e. Smart Array Controller), an Ethernet, Infiniband or other Input-Output module connected nterface component. In some implementations, server system  20  facilitates replacement of a server circuit board  32  without imposing the burden of replacing other server system infrastructure such as server-storage array controllers, ethernet controllers or ports and the like. 
     In addition, module  36  further facilitate changes to the input-output for a server circuit board  32  independent of the server circuit board  32 . In other words, the input-output components for a particular server circuit board may be upgraded or exchanged while the existing server circuit board  32  remains in place. By relocating input-output interfaces and controllers from server circuit board  32 , additional area or space is provided along server circuit board  32  for enhanced airflow and enhanced cooling of the processors or other heat generating components on server circuit board  32 . 
     As shown by  FIG. 1 , module  36  comprises base circuit board  80 , connector  82 , input-output port  84 , input-output controller  86  and auxiliary connectors  90 ,  92 . Base circuit board  80  comprise a printed circuit board supporting one or more input-output interfaces and controllers as well as electrical traces for routing signals across circuit board  80 . Connector  82  comprises a high-frequency mid-plane connection system interface releasably connecting circuit board  80  to mid-plane  26 . Connector  82  comprises 
     Input-output port  84  comprise a port by which input-output signals may be transmitted to and from module  36  from external sources through components on the base assembly (module  36 ) or by another assembly attached to the module  36 . In the example illustrated, input-output  84  comprises one or more ports located at a rear  96  of enclosure  24 . In one implementation, input-output port  84  comprises an ethernet input-output port. Examples of such an ethernet input-output port  84  include, but are not limited to, 10/100/1000 base T ethernet and 10 gigabyte ethernet ports. In another implementation, input-output port  84  comprises a 40 GB Infiniband port. In yet other implementations, input-output  44  may comprise other input-output ports having a capacity of at least 10 GB. In one implementation, port  84  may comprise an SFP+ module a QSFP module or both each capable of supporting 10 Gb per second data transfer rate along with 10/100/1000 base-T ethernet. In another implementation port  84  may comprise an SFP+ module capable of 10 Gb/sec Ethernet along with a QSFP module capable of 40 Gb/Sec INFINIBAND. In yet other implementations, port  84  may comprise an InfiniBand port which is a switched fabric communication link. In yet other implementations, port  84  may comprise other presently available or future available ports are connectors supporting high rates of data transfer. 
     Input-Output controller  86  comprises a communication protocol device to transfer and format data received through port  84  to the server chip set or in reverse from the chip set to port  84 . In other implementations, controller  86  may comprise other controllers or switches. 
     Auxiliary connectors  92  comprise connectors extending from base circuit board  80  to facilitate connection of modular control daughter cards  38 ,  40 . Connectors  92  are offset from one another on circuit board  80  to facilitate concurrent connection of each of modular control daughter cards  38 ,  40 . As will be described hereafter, modular control daughter cards  38 ,  40  provide additional or supplemental componentry relocated from server control board  32  for enhanced modularity. 
     As shown by  FIG. 4 , in other implementations, auxiliary connectors  90 ,  92  may be omitted where modular control daughter cards  38 ,  40  are also omitted.  FIG. 4  schematically illustrates module  96 , an alternative example of module  36  which may be utilized in place of module  36  shown in  FIG. 1 . Like module  36 , module  96  may be provided as part of system  20  or may be provided separately from system  20  after prior acquisition of system  20  to facilitate use of different input-output arrangements or the subsequent replacement of server circuit board  32 . In some implementations, server circuit board  32  may omit such input-output ports and controllers which are now relocated to module  36 , allowing for less complex and less expensive server circuit boards. In yet other implementations, such input-output ports and controllers may remain on the existing server circuit board  32 , but not be utilized. 
     As shown by  FIG. 1 , modular control daughter cards  38 ,  40  connect to module  36  via connectors  90  and  92 , respectively. Although illustrated as connected to circuit board  80  in a side-by-side arrangement, in other implementations, connectors  90  and  92  may project from circuit board  80  by different heights, wherein cards  38 ,  40  are connected to circuit board  80  in an at least partially stacked arrangement. In one implementation, each of daughter cards  38 ,  40  is substantially identical to the other. Each card  38 ,  40  comprises a circuit board  98  and a server-storage array controller  99 . Circuit board  98  comprises a printed circuit board having electrical traces along which data signals and power are transmitted. 
     In one implementation, daughter cards  38 ,  40  each comprise a PCIe mezzanine card manufactured to the IEEE P1386.1 standard. In such an implementation, connectors  90 ,  92  each comprise a mezzanine connector. In other implementations, daughter cards  38 ,  40  may be manufactured pursuant other standards and may have other configurations. 
     Server-storage array controller  99  comprises a device that manages physical disk drives and present such drives to server circuit board  30  as logical units. In the example illustrated, server-storage array controller  99  may manage a portion of internal memory devices  30 . In one implementation, server-storage array controller  99  comprises a RAID (redundant arrays of independent disks) controller. In other implementations, server-storage array controller  99  make comprise other forms of devices for managing internal memory devices  30  and interfacing between such internal memory devices  30  and server circuit board  32 . 
     Although module  36  is illustrated as including a pair of connectors  90 ,  92  for connection to a pair of cards  38 ,  40 , in other implementations, module  36  may be connected to a greater or fewer of such cards  38 ,  40 . For example, in some implementations, a single card  38 ,  40  may be configured to manage all of drives  30 . In such an implementation, one of cards  38 ,  40  may be omitted. In other implementations, server system  20  may include multiple server circuit boards connected to mid-plane  26 . In such an implementation, that  36  may include multiple cards  38 ,  40 , with each card  38 ,  40  serving a different server circuit board. 
     As schematically shown in  FIG. 1 , in one implementation, server system  20  includes or forms a plurality of PCIe communication lanes  102  extending from server-storage controller  98  on the auxiliary or daughter card  38 , across base circuit board  80 , across mid-plane  26  and to server circuit board  32 . In the example illustrated, server system  20  additionally includes or forms a plurality of PCIe communication lanes  104  extending from server-storage controller  99  on the auxiliary or daughter card  40 , across base circuit board  80 , across mid-plane  26  and to server circuit board  32 . In the example illustrated, server system  20  additionally includes or forms a plurality of PCIe communication lanes  106  extending from ethernet input-output port  84 , across base circuit board  80 , across mid-plane  26  and to server circuit board  32 . In one implementation, each of the plurality of lanes  102 ,  104  and  106  comprise eight PCIe lanes. As schematically shown in the illustrated example, service system  20  additionally comprises a plurality of serial attached SCSI (SAS) lanes  108  extending from server-storage array controller  99  to memory device backplane  28  and internal memory devices  30 . In other implementations, server system  20  may be provided with other sets of PCIe lanes and SAS lanes having other pathway connections. 
     Overall, module  36  (or module  96 ) offers several advantages or benefits. First, because module  36  offloads or relocates input-output port  84  and input-output controller  86  from server circuit board  32  to circuit board  80 , module  36  provides enhanced flexibility and modularity to facilitate upgrading, repairing or redeployment of server circuit board  32 , provides a mechanism for input-output modification independent of server circuit board  32  and offers enhanced cooling are providing more space along server circuit board  32 . 
     Second, because module  36  provides a modular or distributed architecture, module  36  may offer high-frequency input and output (greater than 10 GB) with improved signal integrity. In particular, because the chipset data transfer physical layer used to directly connect to the input-output protocol devices (serial attached SCSI (SAS), Serial ATA (SATA), 10 G Ethernet, Infiniband) is close to the external connect point (port  84 ), signal integrity is enhanced. Because module  36  offers a wider port count to storage interface devices, module  36  offers improved bandwidth for storage interfaces such as SAS. 
     Third, module  36  may reduce the overall cost for server system  20 . For example, since circuit server board  32  may omit input-output ports and controllers which are now provided on module  36 , circuit server boards may be less complex and less expensive. Repeating devices for the 10 GB input-output ports may further be omitted from the server circuit board. By using a PCIe to 10 GB Ethernet and Infiniband (IB) adapter or controller  86 , IB repeating devices may also be omitted from the server circuit board. 
       FIG. 5  is a flow diagram illustrating an example method  120  that may be implemented by server system  20  with either of adapters  34  or  74 . In particular, as indicated by step  122 , adapter  34  is mounted to server circuit board  32  and to mid-plane circuit board  26 . As indicated by step  124 , once adapter  34  is interconnected between server circuit board  32  and mid-plane  26 , adapter  34  is utilized to interface at least one of an input-output bus, a server network, management signals or power from server circuit board  32  to mid-plane  26 . As a result, adapter  34  facilitates use of different server circuit boards  32  with mid-plane  26 . 
       FIG. 6  is a flow diagram illustrating an example method  130  that may be implemented by server system  20  with adapter  74 . As indicated by step  132 , adapter  74  is mounted to server circuit board  32  and to mid-plane circuit board  26 . As indicated by step  134 , once adapter  74  is interconnected between server circuit board  32  and mid-plane  26 , adapter  74  is utilized to interface the input-output bus on server circuit board  32  to mid-plane circuit board  26 . As indicated by step  136 , repeaters  26  on adapter  34  further re-drive or repeat input-output signals on adapter  74  to preserve signal integrity or reduce signal degradation. 
       FIG. 7  is a flow diagram of an example method  150  that may be carried out by server system  20 . As indicated by step  152 , a circuit board  80  of module  36  is releasably connected to mid-plane circuit board  26 . As indicated by step  154 , once module  36  (or module  96 ) is connected to mid-plane  26 , data signals are communicated to server circuit board  32  across the input-output port  84  provided on a circuit board  80 . 
       FIGS. 8-12  illustrate server system  220 , an example implementation of server system  20 . Server system  220  comprises enclosure  224 , external storage drives  225 , mid-plane  226  (shown in  FIG. 9-11 ), power supplies  227  (shown in  FIG. 12 ), memory device backplanes  228 A,  228 B (collectively referred to as backplanes  228 ) (shown in  FIGS. 9-11 ), internal memory devices  230  (shown in  FIG. 8 ), fans  231  (shown in  FIG. 12 ), server circuit boards  232 A,  232 B (collectively referred to as server circuit boards  232 ), server adapters  274 A,  274 B (collectively referred to as server adapters  274 ), input-output modules  236 A,  236 B (collectively referred to as modules  236 ) and modular control auxiliary or daughter cards  240  (shown in  FIGS. 9-11 ). Enclosure  224  and mid-plane  226  form chassis  242  for receiving and being connected to the remaining components of server system  220 . Enclosure  224  comprises an outer casing, housing and the like which encloses and supports mid-plane  226  as well as the other components of server system  220 . Mid-plane  226  comprises a circuit board including electrically conductive traces and electronic components by which power and data signals are transmitted or routed between those components connected to mid-plane  226 . Although illustrated as including mid-plane  226 , in other implementations with other architectures or layouts, server system  220  may alternatively use a backplane or other circuit board for interconnecting components of server system  220 . 
     External storage drives  225  comprise external drives, such as hard disk drives, solid state drives and the like which are accessible external to chassis  224 . External storage drives  225  are connected to an associated server circuit board  232 . In the example illustrated, storage drives  225  are accessible at a front end  297  of server system  220  and enclosure  242 . In some implementations, storage drives  225  may be omitted. 
     Power supplies  227  are located at a rear  296  of server system  220  and include interfaces for connection to external power sources such as an AC outlet. Power supplies  227  convert and deliver power at appropriate voltages to fans  231  and to the remaining components of server system  220 . 
     Memory device backplanes  228  each comprises a circuit board upon which internal memory devices  30  are removably mounted for use by server system  220 . Memory device backplane  228  includes electrical traces and electronic components to connect such memory devices to mid-plane  226  and facilitates multiplexing of data or communication to and from each of internal memory devices  30 . Memory device backplane  228  includes connectors  244 , expander rule  245  and mid-plane connector  246 . Connectors  244  are supported or mounted to backplane  228  and facilitate connection of hard drives  230  to backplane  228 . Connector  246  comprises a connector, such as an electronic plug, extending from backplane  228  to connect to a corresponding connector or port of mid-plane  226 . Although illustrated as comprising two memory device backplanes  228 A and  228 B, in other implementations, server system  220  may include more than two memory device backplanes. Although each backplane  228  is illustrated as including  30  connectors  244 , in other implementations, backplanes  228  may include other numbers of connectors  244  for supporting other numbers of memory devices  230 . 
     Memory devices  230  comprise devices for storing and retrieving digital information, such as computer data that are releasably mounted or connected to memory device backplane  228 . Memory devices  230  comprise one or more of nonvolatile, random access, magnetic, digital or data storage devices. In one implementation, memory devices  230  comprise hard drives—rigid or hard rotating discs or platters coated with magnetic material, wherein magnetic head is read and write data to such surfaces. In another implementation, memory devices  230  may comprise other non-transient computer-readable mediums, such as solid state memory devices . In some implementations, memory devices  230  may be fixed to memory device backplane  228 . 
     Fans  231  are located at rear  296  of server system  20  and create airflow through server system  220  to cool internal components of server system  20  such as processors on server circuit boards  232 . As shown by  FIG. 21 , fans  231  and power supplies  227  sandwich input-output modules  236  therebetween at rear  296 . As a result, efficient use of available space within enclosure  224  is achieved. 
     Server circuit board  232 , also referred as a server board, comprises a circuit board supporting server components (processors, memory and connectors) which, together, form a server or computing node for use by server system  220 . Server circuit board  232  carries server or blade components such as processors, connectors, server-storage array controllers, ethernet controllers, dual in-line memory devices (DIMMs), switches, routers, gateways and input-output interfaces or ports. As will be described hereafter, in some implementations, some components of server board  232  may be omitted where such components are now provided by adapter circuit board  274 , input-output module  236  and/or modular control daughter cards  240 . Server circuit board  232 , and its components, facilitate the use of server system  220  to host one or more services or computational tasks on behalf of clients. Depending upon the type of services provided by the server formed by server circuit board  232 , server system  220  may comprise an application server, a catalog server, the communication server, a fax server, a database server, a file server, a game server, a name server, a print server, a proxy server, a sound server, a web server and the like. 
     As shown by  FIG. 11 , server circuit board  232  comprises bus slot  250 , processors  251  and memory slots  252 . Although not illustrated, in some implementations, server circuit board  232  may additionally include an unused connector that another environments is configured to be connected to an inner connector board, such as mid-plane  226 . Bus slot  250  comprises an input-output interface to in the form of a slot to receive a card or riser. In one implementation, bus slot  250  comprises a peripheral component interconnect express PCIe bus slot. In other implementations, bus slot  250  may utilize other present or future developed bus or interface configurations. 
     Processors  251  comprise processing units that perform the services of server system  220 . Memory slots  252  comprise slots for receiving memory modules, such as dual in-line memory modules (DIMMs). In other implementations, server circuit board  232  may carry fewer or greater number of processors, memory slots and memory. Although not illustrated, server circuit board  232  may support other components such as heat sinks, fixed memory units and other electronic circuitry. In other implementations, server circuit board  232  may carry and utilize any of a variety of memory or processors. 
     Adapter  274  comprises a custom interface between server circuit board  232  and an interconnect circuit board, such as mid-plane  226 . Adapter  274  may be provided as part of system  220  or may be provided separately from system  220  after prior acquisition of system  220  to facilitate use of different server circuit boards having a differently configured mid-plane connector interface. 
       FIGS. 13-16  illustrate a detailed example of one of adapters  274 .  FIG. 14  illustrates one of adapters  274  exploded away from and adjacent to one of server boards  232 .  FIGS. 15 and 16  illustrate adapter  274  connected to server circuit board  232 . As shown by  FIGS. 13-16 , adapter  274  comprises adapter circuit board  256 , riser  258  and connector  266 . Adapter circuit board  256  comprises a printed circuit board carrying and supporting riser  258  and connector  266  while including electrical traces  268  electrically connecting components on circuit board  256  to one another. 
     Riser  258  comprises a printed circuit board or card projecting from adapter circuit board  256  which includes an edge connector  259  having electrical contacts or connections for being received within bus slot  250  of server circuit board  232 . Riser  258  includes electrical traces for distributing and routing data and power signals from bus slot  250  of server circuit board  232  to adapter circuit board  256 . In one implementation, riser  258  comprises a PCIe card. In one implementation, riser  258  has an edge opposite to the edge connector that is permanently fixed or attached to adapter circuit board  256 . In another implementation, adapter circuit board  56  may itself include a bus slot, wherein riser  258  has two edge connectors, with one of the edge connectors position in the bus slot of the adapter circuit board  256  and the other of the edge connectors receivable within bus slot  250  of server circuit board  32 . Riser  258  facilitates connection of adapter circuit board  256  to server circuit board  32  using an existing bus slot  50  on server circuit board  232 . Riser  258  facilitates the use of adapter  274  with a variety of different server circuit boards. 
     In one implementation, riser  258  comprises a card extending perpendicular to adapter circuit board  56 . In another implementation, riser  258  comprises a card extending parallel to but spaced from adapter circuit board  256 . In the example illustrated, adapter  274  is illustrated as including a single riser  258  for use with server circuit board such as provided by ADVANCE MICRO DEVICES. However, in other implementations, adapter  34  may include a plurality of risers  258 . For example, with some server circuit boards or server boards commercially provided by INTEL, adapter  274  may include a pair of risers  258  (the second riser  258 ′being shown in broken lines in  FIG. 13 ) for being simultaneously received within a pair of bus slots  250  on such a server circuit board  232 . 
     Connector  266  comprises an interface for connecting adapter  274 , and in particular, adapter circuit board  256 , to an interconnecting circuit board, such as mid-plane  226 . Connector  266  mates and connects with a corresponding connector portion of mid-plane  226 . In one implementation, connector  266  is configured so as to connect to mid-plane  226  using the same connecting portion of mid-plane  226  that would otherwise be connected to an interface or connector of a server circuit board  232 . In other implementations, connector  266  may be configured to be connected to other connectors of mid-plane  226 . 
       FIG. 17  is a schematic illustration or block diagram of one example of adapter  274 . As shown by  FIG. 17 , adapter  274  comprises circuit board  256 , riser  258 , connector  266 , signal repeaters  276 , clock repeaters or buffers  277 , rear signal transfer connectors  292 ,  293 ,  294 , front signal transfer connectors  295 ,  298  and power control scheme or system  299 . Circuit board  256 , riser  258  and connector  266  are each described above. 
     Repeaters  276  comprise electronic circuit chips carried by adapter circuit board  256  which receive signals that are received by riser  258  and re-drive such signals before such signals are passed on to connector  266 . Repeaters  276  repeat signals to preserve signal integrity over large transmission distances. Repeaters  276  preserve signal integrity despite the longer signal transmission distances resulting from the use of adapter  274  where such signals are transmitted across riser  258  and across adapter circuit board  256  prior to reaching mid-plane  226 . 
     In one implementation, repeaters  276  comprise a PCIe driver. In one example, repeaters  276  each comprise a low-power, eight-lane repeater with four stage input equalization and output de-emphasis driver, referred to as a DS8OPCI800 and commercially available from TEXAS INSTRUMENTS. In one implementation, adapter  274  comprises 6 DS80pci402 chips, accommodating 24 PCIe communication lanes in both directions. Each lane is composed of a transmit and receive pair of differential lines composed of four wires or signal paths to provide a full-duplex byte stream in both directions simultaneously. In other implementations, adapter  274  may comprise a greater or fewer of such repeaters  276 , accommodating a different number of communication lanes. In other implementations, adapter  274  may include repeaters  276  having other configurations, accommodating a same or a different number of such communication lanes. 
     In the illustrated example, adapter  274  additionally comprise one or more reference clock buffers  277  for re-driving a reference clock. In one implementation, buffers  277  comprise three zero-delay buffer supports commercially available under the identification ICS9DB102. Each driver buffer support is driven by a differential SRC output pair from an ICS CK410/CK505-compliant main clock to attenuate jitter on an input clock to maximize performance. In one implementation, adapter  274  comprises three of such chips. 
     Rear signal transfer connectors  292 ,  293 ,  294  comprise connectors or headers that connect to cables extending from server circuit board  232 . Connectors  292 ,  293 ,  294  transfer or route signals from server circuit board  32 , across adapter circuit board  256  to connector  266  and to mid-plane  226  for connection to external ports. Connectors to  92 ,  293 ,  294  reduce cabling or cabling clutter within enclosure  224  and simplify exchange of server circuit board  232 . In the example illustrated, connector  292  is configured to connect to the cable transmitting management signals for the server circuit board  232 . Connector  293  is connectable to a cable from server circuit board  232  to receive signals pertaining to server management (ILO). Connector  294  comprises a pair of connectors connectable to a pair of cables from server circuit board  232  for transmitting 1 gigabyte data signals between server circuit board  232  and two 1 GB ethernet external ports at the rear  296  of enclosure  224 . 
     Front signal transfer connectors  295 ,  298  comprise connectors or headers which are connectable to cables from server circuit board  232  which are to be routed to a front  297  of enclosure  224 . Connector  295 ,  298  transfer or route signals from server circuit board  32 , across adapter circuit board  256  to another connector or header  300  which is connectable to another cable that is connected to ports proximate to the front  297  of enclosure  224 . Connectors  295 ,  298  reduce cabling or cabling clutter within enclosure  224  and simplify exchange of server circuit board  232 . In the example illustrated, connector  295  comprises a video/USB/RS232 (a serial port for binary single-ended data and control signals connecting between a DTE (Data Terminal Equipment) and a DCE (Data Circuit-terminating Equipment) connector for transmitting such signals. Connector  298  comprises a power switch and user interface diagnostic (UID) health connector for transmitting signals from corresponding switches or controls at the front of enclosure  224  to server circuit board  232  for turning on or off circuit board  232  and for providing information regarding the health of server circuit board  232 . In other implementations, additional or fewer of such connectors and corresponding routings may be provided on adapter  274 . 
     Power control scheme or system  299  transmits or delivers electrical power across adapter  274  to an electrical cable that is connected to server circuit board  232 . In the example illustrated, power control system  290  additionally monitors or facilitates monitoring of the power that is being delivered and consumed. As shown by  FIG. 17 , power control scheme or system  290  extends from connector  266  and comprises a 12 V integrated electronic fuse  301 , a 12 V standby integrated electronic fuse  302 , a 1.2 V linear register  303 , a 3.3 V linear register  304 , a 5 V standby register  305  and a 12 V/5V standby connector or header  306 . In other implementations, power control system  299  may have other configurations or may be omitted. 
       FIGS. 18-20  illustrate an example of one of input-output modules  236 . Module  236  comprises a device that facilitates modularity and adaptability of inputs and outputs for server system  220 . Input-output module  236  facilitates the exchange, service or upgrade of server circuit board  232  by relocating input-output interfaces and controllers for server circuit board  232  onto a separately mounted structure such that the server circuit board  232  may be exchanged, serviced or upgraded with fewer, if any, changes to the input-output architecture or layout including the associated cabling. In other words, server circuit board  232  may be upgraded, repaired or redeployed with reduced disturbance to an existing external cabling system without a loss of input-output, such as an ethernet or an InfiniBand interface component. 
     In addition, each module  236  further facilitate changes to the input-output for a server circuit board  232  independent of the server circuit board  232 . In other words, the input-output components for a particular server circuit board may be upgraded or exchanged while the existing server circuit board  232  remains in use and in place. By relocating input-output interfaces and controllers from server circuit board  232 , additional area or space is provided along server circuit board  232  for enhanced airflow and enhanced cooling of the processors or other heat generating components on server circuit board  232 . 
     As shown by  FIGS. 18-20 , module  236  comprises base circuit board  280 , connector  282 , input-output ports  284 , communication protocol device  286  and auxiliary card connectors  290 ,  292 . Base circuit board  280  comprise a printed circuit board supporting one or more input-output interfaces and controllers as well as electrical traces for routing signals across circuit board  280 . Connector  282  comprises an interface releasably connecting circuit board  280  to mid-plane  226 . In one implementation, connector  282  comprises a high-frequency mid-plane impact connector. 
     Input-output ports  284  comprise ports by which input-output signals may be transmitted to and from module  236  from external sources. In the example illustrated, ports  284  comprise a dual 1 gigabyte RJ45 connector  308 , a QSFP module, copper direct connect or fiber optic transceiver capable of supporting a 10 GB per second data transfer rate as Ethernet or 40 Gb/s when configured as INFINIBAND, an SFP+ connector  312  capable of a transferring data at 10 Gb per second Ethernet and a RJ45 serial port  314 . In other implementations, ports  284  may include a fewer or greater of connectors or ports as well as alternative types of connectors or ports for facilitating the input and output of data. For example, in yet other implementations, ports  284  may comprise an InfiniBand port which is a switched fabric communication link. In yet other implementations, port  284  may comprise other presently available or future available ports or connectors supporting high rates of data transfer. 
     Input-output controller  286  comprises communication protocol device to transfer and format data received through ports  284  to the server chip set or in reverse from the chip set to ports  284 . For example, controller  286  handles all protocol for communications through ports  284 . In one implementation, controller  286  comprises a PCIe GEN3 end point with a dual 10 GB Ethernet or single 10 GB ethernet and 40 gigabyte Infiniband (IB) controller. In one implementation, controller  286  may comprise a MELLANOX CX3 Virtual Protocol Interface (VPI) device. In other implementations, controller  286  may comprise other controllers or switches. 
     Auxiliary connectors  290 ,  292  comprise connectors extending from base circuit board  280  to facilitate connection of modular control daughter cards  240  (shown in  FIG. 21 ). In the example illustrated, connectors  290 ,  292  comprise mezzanine connectors for supporting daughter cards  240 , respectively, in a mezzanine or stacked architecture. In the example illustrated, connectors  290 ,  292  comprise high-density parallel board connectors such as INFINX connectors commercially available from Amphenol. In other implementations, auxiliary connectors  290 ,  292  may have other configurations or may be omitted. 
       FIG. 21  illustrates server system  220  with portions omitted for purposes of illustration.  FIG. 21  illustrates modular control daughter cards  240  (one of which is seen in  FIG. 21 ). As shown by  FIG. 21 , daughter cards  240  are connected to connectors  290 ,  292  in the stacked or mezzanine arrangement between power supplies  227  and fans  231 . As a result, daughter cards  240  facilitate efficient use of available space within enclosure  224 . Each daughter card  290  includes a server-storage array controller  299 . Similar to server-storage controller  99  described above, each server-storage array controller  299  comprises a device that manages physical memory devices, such as disk drives, and presents such drives to server circuit board  230  to as logical units. In the example illustrated, server-storage array controller  299  may manage a portion of hard drives  230 . In one implementation, server-storage array controller  299  comprises a RAID controller. In other implementations, server-storage array controller  299  may comprise other forms of devices for managing hard drives  230  and interfacing between such hard drives  230  and server circuit board  232 . 
     In the example illustrated in  FIG. 21 , like server system  20 , server system  220  provides a plurality of bus segments or communication lanes, such as PCIe lanes, extending from each server-storage array controller  299  of a particular module  236 , across module circuit board  280  and ultimately to an associated server circuit board  232 . Server system  220  further provides a plurality of bus segments or communication lanes  400  (schematically shown), such as PCIe lanes, extending from at least one of ethernet input-output ports  284 , across module circuit board  280  and ultimately to server circuit board  232 . In one implementation, the plurality of communication lanes extending to the server circuit board  232  extend across an adapter, such as adapter  34  or adapter  274 . In one implementation, server system  220  includes three 8 Lane PCIe bus segments from a server chipset on server circuit board  232  with 16 of the lanes connected to two array controllers  299  and eight of the lanes connected to at least one of input-output port  284 . In such an implementation, a plurality of SAS lanes are also provided from each array controller  299 , across a circuit board  280 , across mid-plane  226  and to hard drives  230  on a memory device backplane  228 . In other implementations, the number and type of lanes and the system components to which such lanes are connected may be varied. 
       FIG. 22  is a top plan view illustrating server system  220  modified to replace an uppermost one of daughter cards  240  with an adapter card  402  that is removably connected to base circuit board  280  of module  236 B by connector  292 . As shown by  FIG. 22 , adapter card  402  includes a PCIe slot  404  receiving a PCIe option card  406 . In one implementation, module  236 B may include the stacked daughter cards  240  as shown in  FIG. 21 . In other implementations, both modules  236  may omit one of daughter cards  240  in favor of an adapter card  402  and an associated PCIe option card  406 . In still other implementations, each of modules  236  may be connected to two daughter cards  240 . 
     Although the present disclosure has been described with reference to example embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the claimed subject matter. For example, although different example embodiments may have been described as including one or more features providing one or more benefits, it is contemplated that the described features may be interchanged with one another or alternatively be combined with one another in the described example embodiments or in other alternative embodiments. Because the technology of the present disclosure is relatively complex, not all changes in the technology are foreseeable. The present disclosure described with reference to the example embodiments and set forth in the following claims is manifestly intended to be as broad as possible. For example, unless specifically otherwise noted, the claims reciting a single particular element also encompass a plurality of such particular elements.