[...]

++

[...Switch from beefy NT box to Sun box...]

You could also convert you x86 box to one of the xBSD or Linux OSs.

With that many simultaneous users, I'd start by looking at memory abuse. MS NT has a pretty horribly bad memory management especially anywhere near the limit.

Anecdote: We wrote and ran some semi-non-trivial (extracted and tweaked from a real application) benchmarks a few years ago and the NT box ran over the weekend and we ended up killing it Monday afternoon. The old Linux v2.0.x box was done in about 30 minutes. Note that this was on the exact same hardware -- that was a dual-boot machine.

If you're trying to actully fix the NT box rather than just switching to something reliable, the second area that I'd look at would be the disk configuration and setup.

ObPeeve: I have never really understood why some folks are willing to trust their *code* to something that is so inherently insecure and as unreliable as an MS OS. Boggles my mind. :-)

Take care, John