Well this was news to me - and it made quite a performance difference on our machines.
Most of us know that you can enable write caching through the Disk Drive entry in device manager.
This articles explains that write cache flushes are sent anyway UNLESS you explicitly tell the system that an uninterruptible power supply is attached - hellooo, isn't my laptop battery a UPS?http://support.microsoft.com/kb/332023/EN-US/
The article explains that - due to a bug - no write flushes were done with Win2K SP2 or earlier.
Now if you have a UPS, or a laptop, or you just wish to take your life in your hands and run like you did on orig, SP1 or SP2, you can download this Microsoft utility to set the system to "power protected" caching. Normally its a CONTACTMS download but it is available from this useful website:http://www.citrix4ge.de/w2ksp4.htm
Just scroll down to Q811392 and download the zip file and run the enclosed dskcache.exe. It changes the registry.
I have a dedicated "scratch" drive for paging, temp files, temp internet files etc etc and this made a huge difference to performance.