NCQ on or off?

Jonnygrunge · 20 Jan 2008 at 14:43

Hi

Iam not hugely familiar with NCQ for HDD's. I have a DS4 mobo. I use the Gigabyte SATA controller for my main HDD for the OS (Deskstar 500GB SATA II)
I use the Intel controller on AHCI mode as I 'hotplug' some old SATA drives for backup.
I have set the RAID controller (Gigabyte) mode from AHCI to RAID/IDE mode in the BIOS, does this switch off NCQ? Will I notice much of an increase in performance? Should I leave the controller on AHCI mode? Can someone advise?
See below my bechmark:

helmutcheese · 20 Jan 2008 at 14:51

I have a Nvidia and see no loss/gain in speed using NCQ, but then again I ideally dont like Intels AHCI Mode.

I seem to remember from reading threads here, that you need be in AHCI Mod etc get NCQ etc (not 100% sure).

Humate · 20 Jan 2008 at 17:46

I saw some performance increase when i turned NCQ off for my raid6 array.

http://forums.overclockers.co.uk/showthread.php?p=10914278#post10914278

rpstewart · 20 Jan 2008 at 18:36

For a single drive there's very little difference in performance with having NCQ off or on, the I/O queue just doesn't get deep enough in normal single user usage for NCQ to make any noticable difference. With RAID arrays however it can adversely affect the read performance by making optimisations that the controller could do without.

steve258 · 20 Jan 2008 at 18:43

Jonnygrunge said:
I have set the RAID controller (Gigabyte) mode from AHCI to RAID/IDE mode in the BIOS, does this switch off NCQ? Will I notice much of an increase in performance? Should I leave the controller on AHCI mode?

Do you have anything plugged into Gigabyte controller? (The purple ones IIRC)
If not than it doesn't matter what you set to this. But it has to be in AHCI to take advantage of all benefits of hot-plug, NCQ...etc. With the Intel controller switching it to Raid mode also enables AHCI as well