Hey Scott, thanks for the response!
I've tried several cache settings, however, right now it is sitting at heavy caching with memory selected. It used to be moderate, however, I changed it to heavy to see if it would help. Doesn't seem to matter much though. In fact, I have no idea what the difference is between heavy and moderate! :)
No RSS feeds actually and really nothing that pulls from any other sources. I forgot to mention this, but I'm sure you guessed it, all the CPU is being used up by the w3wp.exe process. Sometimes it just sits at 5-10% like a good server, but often it does that cyclic spiky-thingy.
My worker processes are set completely default. 1 process, nothing checked in the recycling tab, nothing checked in the performance tab, nothing in health tab but for the 90sec shutdown/startup timers.
But you did bring up 1 thing... is there a way I can check and verify if the worker process is abnormally shutting down and restarting? That would easily cause the spikes and symptoms I am seeing. I don't think this affects anything, but I have a gob of users, about 1,400 portals, and about 20,000 pages, all on 1 DNN server. My SQL2000 server is on another machine so that doesn't come into play.
Otherwise, I still have zero idea : (
Thanks again in advance for all your comments!