Don’t run SATA optical drives under AHCI

Sunday, July 6th, 2008 at 5:43 pm

One of the first things I did when building my new computer was to switch the SATA controller to AHCI. You know, because it is supposed to be better than the IDE emulation mode.

It wasn’t, at least for me…

Shortly after getting it all up and running I found that the system would regularily lock up. But only when burning a DVD which led to a lot of coasters. Thinking it was a driver problem I made sure I was running the latest ones, which partially fixed the problem. Now the burn would still fail, but the system wouldn’t lock up. Instead the drive would just disconnect.

Now I thought it was a hardware problem so I tried different cables, different power connectors and even a different drive (but still a Pioneer). The problem didn’t go away.

At first I researched problems with SATA and optical drives. Many pages ended up pointing to fix (KB928253) that seemed promising. But the fix for that was included in SP1, which I was already running, so I turned to another possibility that involved deleting the UpperFilter and LowerFilter registry entries (KB314060). This seemed like it might be relevant as I had had problems with installing burning software. But continuing the trend, this also didn’t work.

Last weekend I decided to do a fresh install. Partly to see if that would fix the problem, but mostly so I could start with a good install that I hadn’t experimented with. At first I thought this worked. Until the second DVD I tried to burn.

Which brought me to a solution I had discounted. During my research I had found pages talking about how SATA optical drives don’t behave properly under AHCI and the fix was to run them under IDE emulation. I couldn’t see why a recent SATA optical drive wouldn’t work properly under the native SATA mode, haven’t they bothered to implement the spec properly? Or maybe the controller doesn’t?

It has now been a week since I changed back to IDE emulation mode and it as been stable. I haven’t noticed any difference in performance so I’m not really sure what the fuss about AHCI being better is all about.

Aparrently there are motherboards that let you run part of the SATA controller in AHCI and part in IDE emulation. My board, an ASUS P5K Pro, does not support that. But I don’t think that would have affected my choice.

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One Response to “Don’t run SATA optical drives under AHCI”

  1. hi,same conclusions about sata ahci and cdrom/dvdrom drives, although my problem was a bit different – p5k-vm mobo,vista x64 with all updates was locking up on cold boot/power on during loading crcdisk.sys module, during warm boots(reboots) all was going fine. switching to IDE was giving me bluescreens even in safe mode (also during crcdisk), so looks like i am locked out from easy fix and i will have to reinstall as well… rgds,b.

    Bogdan - March 29th, 2009 at 9:48 pm