I am running an AMD six-core 1055T with a 64-bit W7 system. My Gigabyte mobo is capable of fast tranfer rates for SATA drives. My SATA drive is the lowest rating(5.9) on my system efficiency rating of 7.3,7.4!
How do I improve the SATA score?
The Windows Experience Index tops out at 5.9 for hard drives. In Vista, 5.9 was the maximum score, but in Windows 7 they extended the range to 7.9 to cover the better faster performance of Solid State Disks (SSDs). But if you don't have an SSD, you're never going to see a number beyond 5.9 for disk performance.