Thought I would post a heads up regarding a Windows "stability" issue I ran into when I unwittingly updated my Intel storage drivers.
I decided to make RAID 0 array out of a couple of non system HDDs. In the process, I decided to updgrade to the current Intel storage software manager (Intel Rapid Storage Technology).
Soon afterwards I noticed intermittent high CPU usage. This seemed to get worse to the point where my system would be frozen for a few minutes at a time while CPU usage spiked. I eventually had a couple of related BSODs. The BSOD error indicated a "driver power state failure". Though BSODs didn't happen often. For the most part, my system would become unresponsive for seconds to minutes at a time at seemingly random times.
At first I was at a loss to the cause, so I downloaded Windows Performance Toolkit so that I could monitor process activity. I had noticed that it seemed to be the nt Kernel & System process that was causing the problem. Thinking I had somehow messed up my OS, I did a clean install of Windows 7 Pro, X64. After loading all my drivers and updating them, what do you know, I started having the same problem.
After a week or so of dead ends, I tried the process monitoring strategy again using Windows Performance Analyzer. It was getting difficult to actually run a trace while the problem was occurring due to the resulting system unresponsiveness, but I finally got a good reading.
As it happens, the iaStor.sys sub process of the System process was hogging resources like crazy during the issue. So this pointed to the Intel storage drivers. But why was this problem occurring so intermittently?
At first I thought that maybe the ICH9R chipset on my X48 board was failing, or perhaps one of the HDDs connected to it, but this still didn't explain the decidedly random occurence of the problem.
After doing a lot of googling, and remembering the BSOD error of "driver power state failure" I was pointed toward the Windows power-management settings.
Long story short, my HDDs were set under power management to spin down after 20 min of being idle. Whenever they did so, the iastor Intel driver would freak out and the two would enter a loop, fighting each other until either the power management would stop trying to spin down the drive, or until the computer would hard lock. The strange thing is that, with the old Intel ICH9R drivers, this never happened.
So, for those of you thinking about upgrading their Intel Storage drivers, at least if you have ICH9R chipset, don't. I think the driver gets updated automatically when you install the newer storage management utility, and is very difficult to revert to the old driver (I don't know how).
For now, I have mitigated the issue by telling my HDDs to never spin down in the Windows Power Management utility. Can anyone point me to a less "band-aid" fix? Like how to revert to an older Intel driver without having to re-install the OS again?
Edit: Perhaps this should have gone in the motherboard/chipset forum...