Mocha Pro v5 - massive RAM usage

Hi - hope someone can help. I’m tracking a very simple shot, one layer no mattes, footage is 4k. After 600frames or so I’m seeing my memory is almost running out, it’s hitting 55Gb out of 64Gb; the track generally stops with a red box.

I’ve tried disabling GPU tracking (I’m using 2xTitanX 12Gb) - and restarting AE. The tracking is slower of course but the RAM usage spikes just the same. On Windows 10 by the way.

Is this a known issue? Any workarounds I should be trying?

Thanks in advance - Chris

Did a bit more reading around, seems there’s a known memory leak in Mocha. For the moment I’m breaking up the track, stopping every time RAM gets >75% or so; jumping out of Mocha, back to AE, dump the RAM, back to Mocha, carry on tracking, repeat to fade. Hope this gets fixed soon.

This should be fixed very soon, make sure that you stay up on the latest versions of the point releases!


Hi Mary,

any update on this? I’m having the same issue. I expect rendering / processing to run slowly on an underspecc’d machine, but not to gobble up all available RAM only to be frozen by the OS. I’m really close to buying Mocha as it’s doing a great job for a project otherwise, but if this isn’t fixed soon I’ll have to move on :frowning:


What version of the software are you on right now? I thought this was fixed in the most recent version. Let me double check with the dev team.


Please try version 5.5.1 which came out yesterday:

This has massive improvements to memory handling in mocha Pro.

5.5.1 Also does this on lens undistort, about which you’ll (probably) find further information in your Spam folder again, Martin. :slight_smile:

Lowering the RAM usage in Preferences from 80% to 50% stopped it grabbing everything and locking up the OS, although this number was guesswork in my 8GB PC and will vary from machine to machine and even day to day, depending on what else you might have loaded on the same machine.

Rather than it being a % of the physical RAM, making it a % of available RAM at loading time would make it less likely it would exceed this value and cache RAM swapping to HDD and the OS grinding to a halt.

Problem is on playback, when the smaller cache cannot hold all the required frames on longer clips, so it discards held frames and recaches the ones it needs to display.

This discarding and reloading frames makes playback quite slow and the only way to get it to play faster is to play/recache a number of frames, then move the playhead back and replay (some of) them from the cache. Then move forward and repeat throughout the clip.

Probably only real answer (if caching is always required?) is to add massive amounts of RAM to your machine to be able to hold more in cache.

I have just logged a support query on this for 5.5.1 - memory leak is really bad. I also am tracking on 4K footage. Cant get past about 500-1000 frames of simple tracking before complete system lockup due to lack of RAM and disk space. I have 50GB free on my system disk before I start Mocha and I have tried putting the Mocha cache on an external thunderbolt disk.

Thanks for logging this Mark. We are investigating further RAM handling for the hosts as we are getting similar reports for some setups. W

In the meantime your best bet is to:
a) Track at a lower proxy to reduce cache exhaustion (this will also be faster!)
b) If you’re still seeing memory spikes, try reducing the Maximum Memory Usage field in preferences
c) Occasionally close the mocha GUI and reopen to purge the RAM usage

We’ve got people investigating the issue and we should have a fix in the next major point release (5.6).