Forum is very slow after upgrade to latest version?
 

I recently upgraded my forum from 3.6.x to 3.8.4.
Forum pages load is very slow now. I only have around 5000 users and most of it are spammers, I guess.
Web site is very fast.
Forum first pages loads very fast .
Any page inside is very slow and takes 10 to 15 second to load.

Help please..
thx.