power of the memory of nodes.

[Yanosh HRDY]

Hello, I have a question about the memory capacity of the nodes.
Should it be equal to the master pc?
my workstation is 64 GB Ram, is 32 GB for each node is sufficient or should I increase to 64 also?
thank you
Yanosh

[TomG]

Well, that depends on what you plan to render on them - if the scene requires the full 64 GB of your master machine, then each node will need 64 Gb too. So you don't need the memory amounts to match, but if your scene needs more than 32 Gb to render, then the nodes will have the "low / out of RAM" issue.

[jms.lwly]

I have to agree with TomG - if your scenes are pushing 32GB or over of RAM when rendering on your workstation then you'll need more on the nodes.

I have the exact same setup currently, my workstation is 64GB and my render nodes only have 32GB - they work (most of the time) even for my largest scenes but on a couple of occasions the DR Servers have crashed and once or twice caused weird things to happen in the main render too.

[Frood]

The problem is: You cannot judge how much ram a 32GB node will actually need to render a scene by looking at the ram usage of a 64GB box processing it. You still have to actually try it (at least until pass 3 or 4). Memory management of Max+Win is quite inscrutable (for me). Especially the commit size which is the deal breaker (because it is never used but requested, leading to crashes).

I was able to render scenes which use 26GB+ on a 64GB node on 16GB nodes without issues for example. You can sometimes "force" some kind of garbage collection or whatever by starting other applications which need a lot of ram on a rendering node and you see ram usage for the rendering process decreasing by up to 50%. Would be insteresting to send fake "System low on memory" notifications to a rendering max process and see what happens :)


Good Luck

[TomG]

Yes, it's definitely possible that a render on a node will need less memory than on the main machine, and that can't be figured out in advance. That's why matching memory isn't necessary, you could well only have scenes that fit ok on the 32 Gb. However, if you have 64 Gb on the nodes as well, you can be sure if it renders on the main machine, it will render on the node (otherwise, it could still be that the scene on the node will take more than the 32 Gb it has).

[Yanosh HRDY]

Hello everyone.
Thank you very much for your quick and effective help, and your relevant opinions.
It's clearer to me now.
I think I'll use 64 GB on all my machines, it will remove the possible crash of my nodes.
:)
Yanosh