OWC Accelsior S PCIe Adapter for 2.5" SATA III SSD Drives PCIe to 2.5" 6Gb/s SATA SSD Host Adapter, directly mount any standard 2.5" drive Storage Expansion With a Speed Boost, Up to 550 MB/s sustained speeds Install in any available PCIe x4 (or greater) slot-Use as a native, high-speed, boot drive or scratch-disk and boost capacity and performance No drivers or software needed, easily upgrade your PC or legacy Mac Pro tower 3 Year OWC Limited Warranty Directly mount any standard 2.5&#034; drive. Up to 550 MB/s sustained speeds. Enhance SATA 3Gb/s systems with SATA 6Gb/s support. Easy installation. No drivers required. When used together, the Accelsior S and the2.0TB Mercury Electra 6G SSDare compatible with the MacPro4,1 series and MacPro5,1 series. This device combination is NOT compatible with the MacPro1,1 MacPro2,1 or MacPro3,1 series. PCIe 2.0 x4 slot or better is required. Use of a PCIe 1.0 x4 slot will reduce performance. 2009-2010 Mac Pro. Installing Accelsior S into any open x4 or x16 PCIe 2.0 slot will deliver full throughput 2008 Mac Pro. These models have two x16 PCIe 2.0 slots, which enable Acceslsior S to deliver full throughput. Installing Accelsior S into of the two x4 PCIe 1.0 slots will result in Accelsior S being addressed as a gen one, one-lane card with performance limited to real world 190-200MB/s data rates.