Max taking ages to clear memory after render

[stevesideas]

I'm using latest vray on max 2012. The render I am doing at the moment uses a lot of proxies. The actual memory usage goes to 23gb ish. I have 24gb installed.

Watching the windows task manager, once the render is halted or finished the memory usage takes ages to go down to a point where max starts to work again.

Is this just down to my memory speed or is there something else I can do about it ? If for instance I force quit max, the memory goes down very quickly...why can't max do this anyway after a render ?

[vlado]

Is this just down to my memory speed or is there something else I can do about it ? If for instance I force quit max, the memory goes down very quickly...why can't max do this anyway after a render ?

It's a tricky issue; the problem is that during the rendering, memory is allocated in small chunks as needed. After the render is finished, these chunks are freed one by one. Now there is some book-keeping involved to keep track of which parts of the memory are occupied and which are not; the OS doesn't know that most of the memory will be freed anyways, so it constantly tries to "tidy" things up after each piece of memory is freed. On the other hand, when you terminate 3ds Max, all of its memory is freed right away.

We have made some efforts to optimize this process, and we can do more, but it's not trivial.

Best regards,
Vlado

[stevesideas]

Thanks for the explanation. I think for me personally and just as a general observation, scenes are getting more and more complex. Higher geometry, high resolution maps etc etc, so something to speed up this process when it really doesn't add anything of value to the process would be a great help. I can sometimes be sitting there 5-10 mins whilst the memory is being flushed ! Adds up to a lot throughout one day when doing test renders...

[Morbid Angel]

here is one way which is quick, right click - kill process on 3ds max

[Crayox13]

Interesting...thanks vlado...I guess that answers my "unloading geometry" question too.

[stevesideas]

For my particular scene I had a river that used vray displacement. During the pre-processing the vray displacement was being processed and this really really increased render times and memory usage. I decided to use normal maps instead of displacement and this problem doesn't occur any more. I think I'll just have to be more careful in future about where I use displacement.

[Crayox13]

Displacement often kills my scenes too, but then I do clean test scenes for it, and it's ok. Maybe I use too large maps or something, not sure.

[stevesideas]

I subdivided the geometry using turbosmooth by 6 times so maybe I went a bit over top considering vraydisplacement sub divides anyway and the water waves are not choppy...they are only small (as you would find on a river). Displacement for me in this instance was not the best method.

[vlado]

Interesting...thanks vlado...I guess that answers my "unloading geometry" question too.

Not really, that's a different thing...

Best regards,
Vlado