The first thing to do when having preview or render problems is turn of Render Multiple Frames Simultaneously. Second, look at your memory settings. You have to leave some memory for other apps. I would set at least 1/4 of your available memory for other apps. You have set zero. Third, if you look at your MP settings the Actual CPU's that are assigned or will be used for AE is ZERO. That's never going to work well.
If turning off MP rendering and allocating some memory to other apps doesn't fix the problem then I have to ask what is the Comp Size, the Comp Panel Zoom factor and the Comp Panel Resolution. If you have a 4K comp and the Resolution is set to Full and you haven't purged your memory and cache then 40 frames or so may be normal. My recommend Comp Panel settings for RAM preview are, from Left to Right, Zoom Factor - 50%, Resolution - Auto.
Once you get a reasonable ram preview going on, and if you are NOT using temporal effects or effects that are not MP compatible, or are rendering to codecs that are incompatible with MP rendering (most legacy formats are incompatible) then you can try enabling MP rendering for projects that fit the requirements. When experimenting with MP rendering please study this info to optimize your performance: Optimizing After Effects Performance
Dan, this is a widespread issue with AE and MAC. I'm afraid there is no solution for RAM previews and full-renders at this time. RAM is not caching properly and Adobe is saying this is an OSX issue, but I have a machine on Yosemite and a machine on Mavericks, both with the same result. I see that you are on Mavericks.
My machines must be magic because I'm rendering and delivering video every day on Yosemite and CC 2014, CC, and CS6. There has to be something else going on which may involve the codec you're using, your source footage, or other applications you have running.
Thanks for the reply.
I've changed the .mp3 file to a .wav file and that seemed to fix everything, for the time being...
It previewed for 10 seconds fine, but after about 15mins of working on this the RAM preview area has started to shrink again and it's only previewing just over half (5 seconds).
I changed my memory and allocated 4GB to other apps, also turning off rendering multiple frames... (by the way for some reason I can't get my 'actual cpu's that will be used' to change from 0? This seemed odd). Still no change.
I've attached a screenshot of my comp details below, along with a shot of my screen when RAM previewing... (you can see the green bar does not go all the way). I'm not working with ANY footage which is why this is most peculiar, just the wav file so I can edit to the beat.
Once again if there is anything else you can think of...
As of right now Adobe is screaming that it is a Mac issue, but quite simply there is some weird RAM stuff going on with Adobe and Mac. I'm frustrated as I have reported A RELATED ISSUE this issue over 2 weeks ago, independently verified by dozens of Mac users that are also having rendering and ram issues as well... and nothing.
Rick, thank you for the advice. My files are in ProRes 422, so pretty standard. I'm rendering out to Quicktime Animation codec. I will try some other codecs and see if it does anything.