Change in Render Time

Adobe After Effects

Change in Render Time

Posted by Matt Kresling on October 21, 2012 at 8:02 pm

I’m rendering a complex many-layered sequence. When I restart the computer and start rendering afresh, the render time per frame averages 30 seconds. Then, after some time (45 minutes, say), the render time per frame shoots up to 4 minutes. The 4-minute frame differs in no way from the 30-second frame. If I restart the computer, the render time returns temporarily to 30 seconds per frame. Can anyone tell me what’s happening exactly?

I’m running AE6 on a Mac 2×2.8 GHz Quad-Core Intel Xeon with 16 gigs of RAM.

Vishesh Arora replied 13 years, 6 months ago 4 Members · 3 Replies
3 Replies

Angelo Lorenzo
October 21, 2012 at 9:29 pm

Do you have any CPU temperature monitoring software? Most modern CPUs will throttle down their speed if they are nearing temperatures that may damage it.

I would confirm with temp monitoring, and if that is the case then I’d dust out your computer or research some more robust cooling solutions.

Angelo Lorenzo
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Brian Charles
October 21, 2012 at 9:58 pm

Without knowing any of the specifics of the Composition (frame dimensions, effects used, type of footage), nor whether you’re using multi-processing, I suspect that you’ve filled the RAM buffer.

Launch the Activity Monitor and check the RAM usage as the render progresses, my guess is that you’re running out of RAM and the Mac is using VM which is several orders of magnitude slower than RAM, if so you’ll see a large number of Page outs.

16GB isn’t very much RAM these days for After Effects, one option is to use the Secret Preferences to have AE purge memory after X number of frames have rendered.

see: https://forums.creativecow.net/readpost/2/992912
Vishesh Arora
October 22, 2012 at 6:22 am

Matt

If nothing goes well, Split up your render for say 30 min(as you said that after 45 min render slows down) and then combine them afterwords using AE or any other edit program.

Vishesh Arora
3D and Motion Graphics Artist
Films Rajendra

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