Title: SATA Express
Content:   The Serial ATA (SATA) interface was designed primarily for interfacing with hard disk drives (HDDs), doubling its native speed with each major revision: maximum SATA transfer speeds went from 1.5 Gbit/s in SATA 1.0 (standardized in 2003), through 3 Gbit/s in SATA 2.0 (standardized in 2004), to 6 Gbit/s as provided by SATA 3.0 (standardized in 2009). SATA has also been selected as the interface for gradually more adopted solid-state drives (SSDs), but the need for a faster interface became apparent as the speed of SSDs and hybrid drives increased over time. As an example, some SSDs available in early 2009 were already well over the capabilities of SATA 1.0 and close to the 
Title: Serial ATA
Content: Seagate/Maxtor has added a user-accessible jumper-switch, known as the "force 150", to enable the drive switch between forced 1.5 Gbit/s and 1.5/3 Gbit/s negotiated operation. ; Western Digital uses a jumper setting called OPT1 enabled to force 1.5 Gbit/s data transfer speed (OPT1 is enabled by putting the jumper on pins 5 and 6). ; Samsung drives can be forced to 1.5 Gbit/s mode using software that may be downloaded from the manufacturer's website. Configuring some Samsung drives in this manner requires the temporary use of a SATA-2 (SATA 3.0 Gbit/s) controller while programming the drive. The designers of SATA standard as an overall goal aimed for backward and forward compatibility with future revisions of the 
Title: Serial ATA
Content:  Revision 1.0a was released on January 7, 2003. First-generation SATA interfaces, now known as SATA 1.5 Gbit/s, communicate at a rate of 1.5 Gbit/s, and do not support Native Command Queuing (NCQ). Taking 8b/10b encoding overhead into account, they have an actual uncoded transfer rate of 1.2 Gbit/s (150 MB/s). The theoretical burst throughput of SATA 1.5 Gbit/s is similar to that of PATA/133, but newer SATA devices offer enhancements such as NCQ, which improve performance in a multitasking environment. During the initial period after SATA 1.5 Gbit/s finalization, adapter and drive manufacturers used a "bridge chip" to convert existing PATA designs 
Title: Serial ATA
Content:  use with the SATA interface. Bridged drives have a SATA connector, may include either or both kinds of power connectors, and, in general, perform identically to their native-SATA equivalents. However, most bridged drives lack support for some SATA-specific features such as NCQ. Native SATA products quickly took over the bridged products with the introduction of the second generation of SATA drives. , the fastest 10,000 rpm SATA hard disk drives could transfer data at maximum (not average) rates of up to 157 MB/s, which is beyond the capabilities of the older PATA/133 specification and also exceeds the capabilities of SATA 1.5 Gbit/s.
Title: Serial ATA
Content:  SATA revision 2.0 was released in April 2004, introducing Native Command Queuing (NCQ). It is backward compatible with SATA 1.5 Gbit/s. Second-generation SATA interfaces run with a native transfer rate of 3.0 Gbit/s that, when accounted for the 8b/10b encoding scheme, equals to the maximum uncoded transfer rate of 2.4 Gbit/s (300 MB/s). The theoretical burst throughput of the SATA revision 2.0, which is also known as the SATA 3 Gbit/s, doubles the throughput of SATA revision 1.0. All SATA data cables meeting the SATA spec are rated for 3.0 Gbit/s and handle modern mechanical drives without any loss of sustained and burst data transfer performance. However, high-performance flash-based drives can exceed the SATA 3 Gbit/s transfer rate; this is addressed with the SATA 6 Gbit/s interoperability standard.
Title: SATA Express
Content:  2.0 maximum transfer speed, while in the second half of 2013 high-end consumer SSDs had already reached the SATA 3.0 speed limit, requiring an even faster interface. While evaluating different approaches to the required speed increase, designers of the SATA interface concluded that extending the SATA interface so it doubles its native speed to 12 Gbit/s would require more than two years, making that approach unsuitable for catching up with advancements in SSD technology. At the same time, increasing the native SATA speed to 12 Gbit/s would require too many changes to the SATA standard, ending up in a more costly and less power efficient solution compared with the already available and widely 
Title: Serial ATA
Content:  Image, JMicron, and NVIDIA nForce drivers for Windows Vista. In those cases SATA drives do not have low-level features accessible. The eSATA version of SATA 6G operates at 6.0 Gbit/s (the term "SATA III" is avoided by the SATA-IO organization to prevent confusion with SATA II 3.0 Gbit/s, which was colloquially referred to as "SATA 3G" [bit/s] or "SATA 300" [MB/s] since the 1.5 Gbit/s SATA I and 1.5 Gbit/s SATA II were referred to as both "SATA 1.5G" [bit/s] or "SATA 150" [MB/s]). Therefore, eSATA connections operate with negligible differences between them. Once an interface can transfer data as fast as a drive can handle them, increasing the interface speed does not improve data 
Title: Parallel ATA
Content:  The following table shows the names of the versions of the ATA standards and the transfer modes and rates supported by each. Note that the transfer rate for each mode (for example, 66.7 MB/s for UDMA4, commonly called "Ultra-DMA 66", defined by ATA-5) gives its maximum theoretical transfer rate on the cable. This is simply two bytes multiplied by the effective clock rate, and presumes that every clock cycle is used to transfer end-user data. In practice, of course, protocol overhead reduces this value. Congestion on the host bus to which the ATA adapter is attached may also limit the maximum burst transfer rate. For example, the maximum data transfer rate for conventional PCI bus 
Title: Binary prefix
Content: The ATA-100 disk interface refers to 100,000,000 bytes per second ; A "56K" modem refers to 56,000 bits per second ; SATA-2 has a raw bit rate of 3 Gbit/s = 3,000,000,000 bits per second ; PC2-6400 RAM transfers 6,400,000,000 bytes per second ; Firewire 800 has a raw rate of 800,000,000 bits per second ; In 2011, Seagate specified the sustained transfer rate of some hard disk drive models with both decimal and IEC binary prefixes. Computer clock frequencies are always quoted using SI prefixes in their decimal sense. For example, the internal clock frequency of the original IBM PC was 4.77 MHz, that is 4,770,000 Hz. Similarly, digital information transfer rates are quoted using decimal prefixes:
Title: Parallel ATA
Content:  133 MB/s, and this is shared among all active devices on the bus. In addition, no ATA hard drives existed in 2005 that were capable of measured sustained transfer rates of above 80 MB/s. Furthermore, sustained transfer rate tests do not give realistic throughput expectations for most workloads: They use I/O loads specifically designed to encounter almost no delays from seek time or rotational latency. Hard drive performance under most workloads is limited first and second by those two factors; the transfer rate on the bus is a distant third in importance. Therefore, transfer speed limits above 66 MB/s really affect performance only when the hard drive can satisfy all I/O requests by reading from 

Question: what is the transfer speed for sata 1?
Answer: 1.5 Gbit/s.