NewerTech&nbsp;MAXPower USB/eSATA 2x2 Host Adapter for OS X 10.6-10.8.2 Designed specifically for OS X 10.6 - 10.8.2 High-speed USB 3.0 and 6Gb/s eSATA connectivity PCI Express 2.0 x4, USB 3.0 ports x2, 6Gb/s eSATA ports x2 Hot-Swap and Hot-Plug Compatible with Mac Model IDs: MacPro1,1 | MacPro2,1 | MacPro3,1 | MacPro4,1 | macPro5,1 | Xserve3,1; Important Note: Apple OS X Sleep is not supported with this card PCI Express 2.0 x4 Two USB 3.0 ports with Type A connectors (female) Two 6Gb/s eSATA Ports 20Gb/s transfer bandwidth Optimized for all USB 3.0 &amp; eSATA storage devices Backwards compatible with USB 2.0 &amp; 1.1, and eSATA 3Gb/s Hot-Swap and Hot-Plug Mac Pro(August, 2006)<span class="a-text-bold">Model ID:</span>MacPro1,1 (2.0GHz, 2.66GHz, 3.0GHz) Mac Pro (8-core)<span class="a-text-bold">Model ID:</span>MacPro2,1 (3.0GHz) Mac Pro (Early 2008)<span class="a-text-bold">Model ID:</span>MacPro3,1(2.8GHz, 3.0GHz, 3.2GHz) Mac Pro (Early 2009 Quad-Core)<span class="a-text-bold">Model ID:</span>MacPro4,1(2.66GHz, 2.93GHz, 3.33GHz) Mac Pro (Mid 2010 Quad-Core)<span class="a-text-bold">Model ID:</span>MacPro5,1(2.8GHz, 3.2GHz, 3.33GHz) Mac Pro 6-Core(Mid 2010-2012)<span class="a-text-bold">Model ID:</span>MacPro5,1(3.33GHz) Mac Pro 8-Core (Mid 2010)<span class="a-text-bold">Model ID:</span>MacPro5,1(2.4GHz) Mac Pro 12-Core(Mid 2010-2012)<span class="a-text-bold">Model ID:</span>MacPro5,1(2.40GHz, 2.66GHz, 2.93GHz, 3.06GHz) Xserve Quad-Core (Early 2009)<span class="a-text-bold">Model ID:</span>Xserve3,1 (2.26GHz) Xserve 8-Core (Early 2009)<span class="a-text-bold">Model ID:</span>Xserve3,1(2.26GHz, 2.66GHz, 2.93GHz) MXPCIEL2ESU3 Intel-based Mac with available PCI Express 2.0 x4 lane slot <span class="a-text-italic">Backwards compatible with PCI Express 1.0a at reduced speeds</span>* Full-height, half-length OS X 10.6 - 10.8.2 USB 3.0: up to 500MB/s per port eSATA: up to 500MB/s per port Up to 20Gb/s total card bandwidth.<br> <span class="a-text-italic">Dedicated per port performance architecture fully utilizes the PCIe 2.0 x4 bandwidth</span> Via USB 3.0: No Via eSATA: No x2 USB 3.0 Type A ports x2 eSATA 6Gb/s ports none Via USB 3.0: No Via eSATA: Yes Supports all USB communication speed data rate of Low-speed (1.5 Mbps) / Full-speed (12 Mbps) / High-speed (480 Mbps) / SuperSpeed (5Gbps) Supports all USB compliant data transfer type as follows; Control / Bulk / Interrupt NOT Compatible with USB 3.0 &amp; USB 2.0 hubs Compliant with Serial ATA Specification 3.0 Supports all SATA communication speed data rate of 6.0 Gb/s, 3.0 Gb/s, 1.5 Gb/s Supports Native Command Queuing (NCQ) Yes Yes No Sleep is not supported with this Card. The computer&#039;s screen will turn off, but the computer will not actually enter a sleep state with the card installed. This card is not Thunderbolt aware and cannot be used in a Thunderbolt Chasis. 4.72&#034; x 4.53&#034; x 0.75&#034; (12.0 x 11.5 x 1.9 cm) 0.43 lbs (0.19kg)