extremecarverWP-Supercache somehow does not really work on my site (http://openmtbmap.org). I got kicked out from my first webhoster because too high CPU usage (okay it was a cheap plan, and 1000-3000 visitors daily are maybe a bit more than they expect you to get if you pay 3€/month, as well as having 1-2GB traffic per day (mainly pictures)- but the culprit seems to have been the cpu usage and not the traffic.
Now i have a dedicated server. CPU is a Celeron 2.66 Ghz, 1GB Ram, Suse 11.1, kernel 2.6.29.4, administration with plesk, so nothing outstanding, but I suppose that it should be enough for running a wordpress blog with around 150 pages and average 2000 visitors with 10.000 pageloads per day. Maybe the number is actually a bit higher, because wp short-stat registers around 2x as many referrals as wordpress.com stats.
the good thing is that once a site is cached, it gets served very very fast, however it takes up to 20 seconds to cache the page. without wp-supercache pages get generated in 1-2 seconds, and cpu usage averages around 0.3. Enabling wordpress.com-stats without wp supercache has more or less no impact.
With wp-supercache after deleting all cache cpu usage runs around 2 (remember it's a single core) for the first 10 minutes and after around 3-4 hours goes down to around 0.4. If additionally I enable wordpress.com-stats my server has a hard time not to crash after deleting cache. with wp-stats enabled cpu usage averages around 0.4-1.5 so I have to disable it (this is after 10 hours not deleting the cache, in the beginning it's much worse).
Additionally google-analytics doesn't work with wp-supercache for me (it actually shows the connection, but in my ga account no pageviews show up - without wp-supercache it works fine). I tried it via plugins (ultimate google analytics and 2 other ones) as well as via theme options (I run atahualpa, which in my eyes is really bogging down my site, but it's so nice and easy to customize I can't get around of ditching it).
I now changed expiration time to 10 hours, which somewhat gives acceptable performance
Other plugins I run to optimize performance (current versions):
c sprites for wordpress
php speedy wp
