I have a Mac Pro 5,1 8-core, OS X 10.7.5(so I can connect to good ol' Avid Unity) 32GB 1066mHz ram, Quadro K4000 w/ cuda card, running the most recent version of After Effects CC. I am rendering short clips that usually take 5 minutes, but all of a sudden, after restarting I can render one thing, and then every subsequent render takes roughly 4-5 times what it should. I power down or restart, and it goes as quickly as it should. I have cleared the caches, but it doesn't seem to have much effect. I haven't seen anyone else reporting this specific issue, so if anyone has any idea what's going on, I'd greatly appreciate it!
What effects are in your comps?
What are your memory and multiprocessing settings?
What exact version number of CC are you running?