I'm running After Effects CC on an iMac w/Mavericks and 12 G ram.
I'm dealing with ~180 frames of 1920x1080 video, including a cinema 4d render (jpg sequence) and a cinema 4d file, which is inactive.
For the duration of this project I've been able to render full resolution ram previews with no problems, and they processed pretty quickly. As of a couple hours ago, two things started happening:
1) The render bar started to constantly cycle even when I wasn't clicking anything and hadn't requested a preview.
2) RAM previews would fail with the classic "you must have at least two frames."
I've pared down my system memory use by closing apps and background processes, purged inactive memory via the terminal - none of it worked.
Any idea what caused the shift? I upped my memory allocated to AE and switched to half-res RAM preview, which has me working again, but I'm really confused about why 1) and 2) happened suddenly. According to my system monitor I have about 4G of RAM unused. I was only updating my assets in C4D and Photoshop, then rendering out image sequences that AE was consuming - no changes on the AE side.
Hmm...I kind of figured this out while debugging (see info below).
I deleted my two Pixel Motion Blur effects and re-applied them. Now everything is working fine. I had tinkered with the settings, but believed I had reset them.
Prior to doing this I had done the following tests:
There are 4 layers in the comp:
1. 3D Tracker Camera
2. JPEG Sequence (shadows w/multiply)
3. Pre-comp (Containing 2 JPEG sequences, one masking the other)
4. MOV file
If I invis all of these layers EXCEPT the pre-comp (3 only), but invis everything in the pre-comp - so there are no visible layers being rendered - changing frames still spends around 5 seconds on compute, and it appears to be doing background work all the time. Disabling pixel motion blur makes this instantaneous.