we seem to have an issue with our SQLserver/MSserver machine.
The machine has dual processors (1.33ghz) with 512 of ram.
within task manager we see that cpu is pegged and that the biggest culprit is sqlserver.exe. We notice that i/o writes are 139 billion bytes and growing whilst looking at it (note: machine has been up for 18 hours, another machine has 203 billion bytes written but has been up for days). Another stat that we find interesting is that sqlserver.exe's mem-usage is 156mb of the 512mb available...leaving over 200mb free.
On the machine that has normal cpu usage, it has the stat of mem usage of over 700mb of 896 total ram and the i/o writes of 203 billion over a period of several days if not weeks.
on both machines the Sqlserver Memory option is set identical in that Dynamically Configure SqlServer Memory is set to true and Minimum is set to 0 and Maximum is set equal to the amount of ram in tha machine.
The suffering machine DOES NOT have a SA password, which prompted us to look for evidence of the latest WORM that searches for servers without SA passwords...we have done virus scans and physically looked for the *.js files and registry settings that Norton says will be present if infected...and came up with nothing.
We've stopped the Alerts, and verified that each database on that server has the AutoClose parameter set to False.
Do you happen to have any protection from SQL Slammer? The symptoms you describe are somewhat similar. SQL at or near 100% cpu, no obvious process using CPU. To be sure, check in sp_who2 for long running queries, or in profiler for lots and lots of little ones. Good luck.