Hello there, my first post here...
I have installed (successfully) an OCZ-VERTEX3 60GB SSD on my computer as my OS drive, and used the extra SATA plug and cable that came with the package to place the original 500GB hard drive in the other slot. However, while the Hard drive is SATA300 (SATA-II, I guess), the SSD is indeed, SATA600 (SATA-III?). However, using benchmark tests, my SSD is is pulling numbers typical of an SSD plugged into a SATA-II port... Considering that the G74Sx should have SATA-3 capabilities, I do not understand why the SSD is running at a SATA-II (<300Mb/s) performance level. I have had this SSD for at least 2 months, so I understand if there is slight wear. My model is the G74Sx-TH71. (I am hoping I was not given SATA-II ports :(...)
AHCI is enabled, as well.
Any help is appreciated! I'll give more information, if necessary.
(I haven't updated the BIOS G74Sx.202 to version 203.)
Motherboard information:

AS-SSD benchmark: