if I play a clip of video footage (prores) in a comp it plays in realtime (after RAM preview). When I change the bitdepth up to 32bits, it still does playback in realtime. But when I change the color mode to a linear workspace it doesn't play in realtime anymore, it does only do 5/25fps.
Is there a way I can still (RAM)preview the comp in realtime in AE when I'm using a linear workspace?
I'm working on this machine:
MacPro later 2013
2x AMD FirePro D700 6144MB each
AE CC 2015 represents the first step in a major overhaul of AE's architecture. Unfortunately, it's just the first step and it isn't completely there yet. It has a number of big issues - especially with things like previewing. While this massive change is good for the future of AE, it isn't necessarily good right now. Think of CC 2015 as a beta where we can test some of the new features and it is a lot less frustrating. Now, there is an update for CC 2015 coming out "at the end of the month", so your issue might be fixed then.
In the meantime though, try using CC 2014. It tends to have fewer issues in general. See this page for downloading older versions: http://blogs.adobe.com/adobecare/2015/06/16/how-to-find-and-install-previous-version-of-ad obe-apps-in-cc-2015/ Let us know if that works for you.
Thank you for your answer. Will try 2014 for some projects then.