Need some expertise please. Just built a nice system with OS XP, a WD VelociRaptor 150 3.0 Gbit/s, ASUS Rampage INTEL X48 MB, x2 ASUS CrossFire 4870's, INTEL 9550 Core2 Quad which supports this speed.
As there is only a single drive and predominantly this will be used for games I left the default to IDE in the BIOS so XP finds the drive without having to load a RAID driver available (F6).
In hindsight I'm wondering if I should have set it to AHCI (SATA), or RAID. The key benefit as I understand it is NCQ which this HD supports. However, some say there is no real performance benefit and other experts like here http://en.wikipedia.org/wiki/Native_Command_Queuing actually say NCQ can slow games down.
I've seen how one can change the IDE to AHCI by loading drivers first and then changing the BIOS setting which will give the NCQ in effect. I also seen that INTEL recommend setting to RAID rather than AHCI for stability. What I can't see is a definative Advantage/Disadvantage of runninig this nice SATA drive set as IDE in the BIOS, e.g. (is it using the old ATA bus, or something like that).
So, is there any definative benefit(s) for changing a single SATA drive BIOS set as IDE to AHCI/RAID in my application?
Just as you said, by loading the driver you will now have NCQ.
There is not much real world benefit to it, your drive is still working at it's rated speed...it is not using the ATA buss. However, it is in your best interest to make sure you have the latest SATA chipset drivers loaded for your SATA controller. The standard Windows drivers sometimes will not net you the full speed of the SATA controller.
Run HD tune, and check the speed/transfer rates of your drives. If they are running way lower than they should be, you may need to download and install the lastest drivers for your SATA controller from the motherboard manufacturers website.
You'll see a minimal performance improvement when the queue depth is large enough to take advantage of NCQ. That occurs more often on busy servers than PCs where NCQ can slightly decrease performance. If you decide to set SATA to AHCI or RAID, make sure that you install Intel's latest Matrix Controller drivers. I didn't on my Windows Server 2008 and I ran into issues when copying large amounts of data (400GB from a folder to another one on the same hard disk) and I had to run chkdsk to fix it. If you use tools like BartPE, also make sure that AHCI drivers are loaded; otherwise it won't see your hard disk.
Thank you all for taking the time to reply. I'll try the HD Tune just to make sure as suggested and probably leave as is, i.e. (IDE) as confirmed there is no real benefit in my gaming application. I can sleep at night now knowing the drive will be fine