As of late something has changed in my RAM previews. It does not play smooth anymore, but is skipping frames, pausing and speed changing all the time. It looks like I'm trying to play an uncompressed full-HD Quicktime from a slow disk. In the past 15 years of using after effects I've never seen this. It either plays or it does not, this way it's useless.
First I thought it might be the complexity of my comp (should not matter once it's rendered, but still) so I created a simple (HDTV 1080 25) comp with a small solid moving from left to right. Same jerkiness, wether I preview in full res, half res.
I'm working with AE CC on a MacPro, 32 GB of RAM. Preview is set to computer monitor only. I've played with memory settings (now set to 26GB to AE) but this does not seem to change anything.
Am I missing a new setting somewhere?
Ram preview appears to be better with multiprocessing on, but even with 3GB per thread I get warnings about frames not being rendered due to not enough RAM when I do a 'real' render.
And of course this still does not explain why my RAM-preview suddenly goes crazy while it has been working fine for years. Once the sequence is rendered and stored in RAM it should not matter how the processors were used during rendering I think.
Anyway, I'll keep MP on for now, just have to remember to turn it off for the final render.