Tutorial : How to switch from IRRT to AHCI mode - E6400/E6500 (Vista)

I don't have any GM45 based system running XP here, but I'll try to see if I can help you guys with this if you're willing to test it out.

1. Create a restore point and if possible a system image with Ghost or Acronis (if you have it).

2. Download the zipped AHCI reg file I attached on the first post of this thread and install/merge it.

3. Download Dell's Intel 8.2 drivers to you desktop I linked to in the first post.

4. Restart the system, F12 to bios and change to AHCI.

System should boot and now detect the GM45 AHCI controller. Don't restart and run the Intel driver installer that you saved earlier to your desktop. Check device manager for the Intel AHCI controller is correctly listed, then restart the system.

Let me know how it goes.

 

Yes that's right. I had it and it was really good but size was to small so I sold it and I'm now looking for a bigger drive such as Supertalent Ultradrive.

 

OIC. What exactly makes the 8.7 drivers buggy in AHCI mode?
Rgds.

 

I can only speak for my experience, but I was having extremely bad DCP latency with 8.7. When I reverted to 8.2 a lot of the latency disappeared (but not all). Then I switched to AHCI and ALL of the DCP latency went away.

That said, I highly recommend MiB's tutorial.

 

I am using a MLC SSD and was getting performance issues when using Media Center. This seems to go away in ACHI and the system is overall more responsive.

 

Good to know, thx!

 

The good news: the installation went off without a hitch using your method/reg key, and now AHCI mode works just fine. THANK YOU!

The bad news: I'm still getting a random red DPC spike every thirty seconds or so. This doesn't seem to affect the built-in audio--but if I'm using my M-Audio USB device for recording or audio editing, red spike = death. (Red DPC spikes cause M-Audio's ASIO drivers to crap out, basically, which destroys any in-progress recording.)

 

Are you using your external eSata port at all for anything? If not, try turning it off in the BIOS and then test again.

 

I've already got it disabled, actually; also, I've disabled the network card, firewire, fingerprint reader, and docking station ports.

 

Thanks for your good news that this worked on XP as well, and that the latency issue is resolved for your onboard audio.

If you only see this DPC spike for the M-Audio device on USB, but not the onboard audio, look into what else you have connected on the USB bus that could be the source.

Sometimes mouse drivers continually poll via USB (logitech is bad for this).
Tablets, usb multifunction printer fax software drivers etc.

Silly question maybe, but if onboard audio is ok now - why not use it ?