For some reason my older projects are now rendering in hours (if ever) when they used to take minutes. I have tested on 2 similar macs with the same result. Using latest AE, latest OSX, latest QuickTime. I have 8gb ram on an 8core mac, not ideal but it was all working perfectly before christmas. I have even disabled the render simultaneous frames etc with no luck. Maybe an os update has busted something? Is anyone else having problems?
Just noticed the auto updater did not tell me of a point release, hope it fixes this.
So far I have been really disappointed with memory management in AE.
Please provide more info on CoDecs used in teh projects, graphics card and so on. Quite possible that the 10.5.6 update or an QT/iTunes update made a mess, but without further details there is no way of providing help.