So I installed my new Gigabyte 990FXA and in the CD for it, it has a ACHI/RAID driver I can install. I already changed the mode in BIOS to ACHI. Would this driver benefit me in any way?
It's probably out of date anyway. And plus it's more for before OS install. Although you might benefit a little from downloading and installing the latest one off the manufacturer site.
The ACHI driver between the 970 and 990 is the same. If you did a reinstall use the one off Gigabyte site like said. Even if they list the driver under a new date, I dont think the ACHI driver has been updated in a long time.