Cannot boot in AHCI mode.

[Mychael]

My Mobo has the capability to support AHCI (Advanced host controller Interface) and my HDD is modern enough to support NCQ (Native command queuing), however if I try to enable the AHCI mode in bios it wont boot past the windows splash screen.
When I first enabled it I got a box telling me things were being enabled and then it required a re-boot.
Is the reason it wont work because I should have had AHCI enabled from the start or because my HDD came from a system that did not support AHCI and are now irrevocably configured to run in ide mode which configures the SATA controllers to ide mode.
I don't have RAID but if I've understood correctly AHCI is not for RAID but just to run the drives more efficiently.

 

[Mychael]

I've been googling a bit and it seems as if my question is the answer, as I installed my O/s's under IDE mode then AHCI wont work from simply making the change in the bios.
The common consensus also seems to be that efficiency gains in the real world are not significant enough to bother with.

 

[Nibiru2012]

From Guru 3D.com:

To answer that question (and I do this safely with all Intel ICHR9/10 chipsets) there is a way to safely enable AHCI mode. Here we go:

1. Startup "Regedit
2. Open HKEY_LOCAL_MACHINE / SYSTEM / CurrentControlset / Services
3. Open msahci
4. In the right field left click on "start" and go to Modify
5. In the value Data field enter "0" and click "ok"
6. exit "Regedit"
7. Reboot Rig and enter BIOS (hold "Delete" key while Booting

In your BIOS select "Integrated Peripherals" and OnChip PATA/SATA Devices. Now change SATA Mode to AHCI from IDE.

You now boot into windows 7, the OS will recognize AHCI and install the devices. Now the system needs one more reboot and voilla ..

I don't care what is written about it, for me AHCI makes my system run faster, smoother and more responsive.

I have use AHCI since I built this new system and the for those with spinner HDDs, the NCQ is a very useful feature.

From Wikipedia:

Native Command Queuing (NCQ) is a technology designed to increase performance of SATA hard disks under certain conditions by allowing the individual hard disk to internally optimize the order in which received read and write commands are executed. This can reduce the amount of unnecessary drive head movement, resulting in increased performance (and slightly decreased wear of the drive) for workloads where multiple simultaneous read/write requests are outstanding, most often occurring in server-type applications.

It's also a good idea to install the latest Intel RST driver for your chipset. (Rapid Storage Technology).