We're running a somewhat large site and have recently started have performance issues.
If I open FireBug in FireFox and loads up a page, it'll sometimes wait for 6-7 seconds, before receiving the initial page.
After maybe 6-8 requests, it'll start serving them with a minimum of wait time (10-20 ms)
We're hosting the site on Windows 2008 R2 running IIS 7.5. The site is in asp.net 3.5.
We're also logging the time from PreInit to PreRender, and it's seldomly above 100ms, so it's not the code or database, which causes the initial wait of 6-7 seconds.
We're at a loss here, so any help is highly appreciated.
EDIT: We've just discovered that it is in fact the DB, which is causing the trouble. Every 3 minutes a single core peaks in kernel time, and this corresponds with when the site is slow.
Next step is to figure out whether it's a driver or whatnot. (It's the system process)