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AE 7.0 RAM preview playback issues – possible explanation
I’ve checked a few threads on this, but now I too, have a RAM playback speed issue … which I’ve never seen in 10 years of AE usage.
The playback isn’t full frame rate, the audio is out of sync, and sometimes the audio simply doesn’t play for the last few seconds of the RAM preview.
One would assume that once the frames were cached in RAM, they would play back with no speed issues. The amount of RAM only affects the number of frames available, and processor speed affects the time to render & cache each frame. So … RAM playback speed is affected by the speed of data transfer from the RAM, yes?
Well, when I’m at half or quarter res, I get 29.97 (sometimes 29 or 30 …) and no audio issues. I only notice problems with full frame, 29.97 playback, when the RAM usage goes over 2GB or so.
Why is this significant? I just installed 2GB of new RAM, taking it from 2.5GB to 4.5 GB.
It’s Shikatronics, from Carbon Computing in Toronto. The system calls for PC3200 DDR400 and this RAM is PC3200 DDR400. Yet there are playback issues. I’ll take out the new RAM, and see what happens, but I think the message is clear.
I just thought this might help someone with similar issues.
(G5 PPC (2nd rev), dual 2.0 GHz, 4.5 GB RAM, OS 10.4.7, AE 7.0)
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4 Replies
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Ah, but now the problem happens at full res even when the RAM usage is well below 2GB, possibly indicating that the new RAM (in the last 2 slots) hasn’t kicked in yet.
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IF the issue first arose after installation of the new RAM, its a good bet that the RAM is the culprit. Due to OS cacheing and general overhead that RAM my be used below the 2GB threshold you mention.
Could be that the latency of the RAM doesn’t match other installed RAM. Check in System Profiler.
Have you tried removing the RAM to see if the problem persists?
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Regarding latency, the original RAM is 330, whereas the new RAM is 440. Could that be a problem?
Regarding your suggestion of removal, I’ll try combinations of:
– old RAM only
– new RAM only
– new RAM in slots 1&2, with old RAM in the othersI’ll get back to you once I’ve done that.
Thanks,
Steve -
Troubleshooting RAM problems is very time consuming.
There is a utility for OS X called MemTest which can automate the process. It runs a variety of tests on the RAM but takes hours to complete. Best done overnight.
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