RAID is for using multiple disks as one, your referring to AHCI (Advanced Host Controller Interface). Your motherboard has IDE cable slots in it, and so when it is using IDE devices, all drives are now in IDE mode, thus limited to 150Mbps speed. If you are using only SATA devices, then switching to AHCI in your BIOS will give you full SATA II speeds (300mpbs) double the speed. The only thing is you need to make some changes in windows before you switch the settings or else you cannot boot. There are a lot of instructions online, google switching from IDE to AHCI in windows and there should e a number of tutorials to help you.