so far we never saw such dramatic performance decrease during our testing so we are definitely interested in more info.
* Could you please describe what's your typical use of your mac?
my typical use is mainly for application developing and music production
What kinds of applications are you running when you see the performance loss?
Xcode 4.2.1, VirtualDJ 7, TechTool Pro 6, FL Studios 10, GarageBand, & Sometimes even Firefox!
Do you often work with large files? Are you using with some input/output intensive applications?
Yes Xcode 4.2.1 (but performance loss was never a issue until Avast 3600b was installed)
Can you try to disable filesystem shield (in System preferences >> Avast >> Shields) to check that's the culprit?
i've uninstalled Avast And removed all files linked to Avast after the uninstall and performance was great once again then i installed Avast again and performance dropped!.
Can you either check system logs if there is anything suspicious, or upload them so we can take a look in them? (/var/log/system.log, /var/log/kernel.log, /var/log/fileshield.log).
every thing looks ok to me i think