I'm attempting to figure out why our intranet is having performance issues. From some basic troubleshooting, I'm leaning towards the issue being our SQL server, which is hosted on a separate server. Basis for this was a quick test of hitting basic pages, which come up quickly. Pages that have any sort of database connection have random load times. Sometimes they load in no time at all, sometimes they take over a minute to load.
I've taken a small look at the database using SQL Profiler, and from what I can see, it really is getting hammered pretty hard. I'm not a professional DB admin, though, so what I think as getting hammered could be well within tolerance limits. I ran the performance tool on the server, and that doesn't seem to be showing any signs of distress. Processor % and network bandwidth have spikes, but they don't go over 50% very often. In the event of a slowdown, I would expect to see the CPU spiking to 100% and staying there, or maybe network bandwidth, or something.
So, my question is, am I looking at the correct metrics to correctly diagnose this issue? If I am, are my performance assumptions valid? Are my basic assumptions even valid? A link to either IIS or SQL server performance diagnosis information or tools would be extremely helpful in figuring out what's going on. Even a general idea as to what to look for would be really appreciated.