I've been looking everywhere and everyone seems to say that you should put it in AHCI mode for max performance..
Here's my setup though:
Single SSD X25-M 80GB connected via ICH9R
2 2xHDD RAID0 (4xHDDs (2 RAID0) connected via ICH9R
now obviously the BIOS is setup as RAID and not AHCI, would I be loosing any performance by doing this? Also should I be using Windows RAID drivers or Intels or Gigabytes (Using Gigabyte motherboard)
If you are set to raid in the BIOS the single drive will be effectively be running in AHCI. Also as the drive is not part of the drive array you will also be getting TRIM You are good to go.
To get TRIM support on a single SSD with other RAID arrays you need to have RST 9.6.