ATTO ESAS-H644-000 PCI-Express 2.0 Low Profile SATA I, II / SAS 4-Internal/4-External Port 6Gb/s ExpressSAS H644 Host Adapter External Connectors: 1 x SFF 8088 Mini SAS (x4) Internal Connectors: 1 x SFF 8087 Mini SAS (x4) Transfer Rate: Up to 9.6Gb/s Part: ESAS-H644-000 Dimensions: 5.60L x 2.73H Operating Systems Supported: Windows Server 2003, 2008, Windows XP, Vista, 7 Red Hat & SUSE Linux Mac OS X (10.4.x - 10.6.x) VMware ESX Server 3.5 VMware ESX Server vSphere 4.1 Parts: 3 years limited Labor: 3 years limited