SATA II

ok, just because the HDD has a Sata 3.0Gb/s doesn't mean the HDD can actually go that fast

even SSD's can't do that yet (though very close with ~250MB/s)

You have 140 MB/s burst speed (original SATA was spec'd at 150 max, SATAII at 300), and sustained transfers at 74. One of the great aspects of the SATA promotions has always been that the sustained transfer rate is nowhere near the max rate. In fact, lots of people argue that the 300 number for SATAII is just "fluff" because on most systems none of the SATA devices will exceed the original 150 number. At least, not yet. Bottom line, I suspect the sustained average transfer speed you are seeing is normal.

XP (including SP2) does not have built-in SATA drivers, although they can be installed after XP is running. However, that usually does not allow you to boot from a SATA device. To do that, you have to install those drivers at the very first stage of Windows Installation, using a floppy disk as the driver file source. However, to avoid all that, may mobo makers include a cute trick in their BIOS, and often make it the default setting. This is an option to have the BIOS take over low-level control of the SATA ports and Emulate an IDE port. This makes the SATA device look to the rest of the world (read, Windows) as if it were a simple IDE device, and Windows DOES have a built-in driver for that! That's the easy way to install and run Windows from a SATA drive.

Thanks guys!