If you mean PAH is slow when you first start it, that can be because you have a lot of old hand history files which haven't been moved out of the hand history folder by PT2 after it finishes importing them. With all your poker software closed down, have a look in the HH folder and move any old files out of the way, into your 'processed' folder.
It sounds more likely that the cache would help your situation, though.
(Unless you are using postgres 8.3 which doesn't work with the cache.)
Please enable logging, restart PAH then enable the cache and click Rebuild Now. This can take quite a long time if you have large databases so you may want to run it overnight.
If it fails to build correctly, attach the PAHud.log file to a ticket on our
Support system so that we can review your configurations and troubleshoot the issue.
Tutorial: How to Create a Log File