Author Topic: rendering on a farm....memory optimisation correlation?  (Read 1423 times)

Offline 01kingj

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rendering on a farm....memory optimisation correlation?
« on: October 12, 2011, 02:43:35 PM »
hi guys.... setting off some renders using 'smedge' submitter over a farm, getting some awful render times. any tips and tricks?.... the renders on my single 8 core box are spanking the 24 core blades.

i realise the blades are carrying 3 jobs at once...but even still, individually the jobs are taking 2/3/4 times longer than rendering single frames.

i see some settings regarding memory....pre allocated sub div cache.... which defaults at 1200. theres also a little tick box there.... can anyone shed some light on this.

thanks guys and gals.


Offline jo

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Re: rendering on a farm....memory optimisation correlation?
« Reply #1 on: October 12, 2011, 09:45:07 PM »
Hi jk,

I'm not sure what your problem is in general. However I did recently do some documentation relating to the preallocating the subdiv cache which you can see here:

What I haven't got around to adding yet is the fact that the 64 bit version calculates a larger default size for the subdiv cache.

Why are you running 3 jobs per blade? Are you explicitly setting the project to use 8 threads (i.e. 24 cores 3 jobs = 8 threads each). If you aren't doing that then TG2 could be trying to use 16-24 threads per job, which could be causing some performance issues. Or it might not!

The other aspect could be RAM. With 3 projects running at a time that all used a fair bit of RAM you could potentially run into VM paging issues if the blades didn't have a lot of RAM.



Offline Tangled-Universe

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Re: rendering on a farm....memory optimisation correlation?
« Reply #2 on: October 12, 2011, 09:55:25 PM »
It's also definitely worth going through these thoroughly:

Basically it means dozens of things can cause the poor performance, mostly it are common mistakes which the above 2 links should help everybody with.
Else, it is always very scene specific. Depends on if your scene is model-heavy, lots of clouds, both, whatever...every scene needs a bit of a different approach to really optimize it.
Besides that it's also possible the rendersettings are good, but the scene design is ineffecient or uses inappropriate settings.

For specific help you could post a render to show what it is and post your rendersettings along, preferably by copying the rendernode straight into the forums as it is XML based.
Best is to post the complete tgd so we can see it as a whole, if possible.