RAM unload after render taking extremely long

[Art48]

Hi,

I have a RAM-heavy scene (takes about 33GB of RAM peak) which is using displacement.
When I cancel a render it unloads the RAM at about 20MB/sec according to my estimation from the Task Manager.
You can imagine it takes ages until the machine becomes responsive again.

Any way around it? Reasons?

[Richard7666]

I used to get this with vray 2.x for Maya. Could take 5 minutes to unload the scene from RAM*

Haven't run into the issue with 3ds Max / vray 3.0 but I probably also don't go overboard with displacement like I used to as a beginner. Smaller map sizes, more optimized settings (basically just the defaults with 32 subdivs)


*would the reason it takes so long to unload be because it's not actually RAM per se, but the system page file? caused by going over the amount of actual RAM the system has? Though my page file resided on my SSD...

Though in your case I see you have 64gig and only 33 in use, so page file use probably isn't anything to do with it

[Art48]

Thanks for your reply.
I propably don't go over board with the displacement settings but I need fine settings for my stuff to work

[Macker]

I've been having this problem too, but never thought to check the speed of the RAM.

[thomashl]

Did you have many render elements? I've experienced the same issue and it seems to start happening when I have lots of render elements.

[Richard7666]

I've been having this problem too, but never thought to check the speed of the RAM.

Speed of the RAM wouldn't be relevant for something like this.

[Art48]

Well I do ahave a few, but nothing out of the ordinary.
Anyways the project is over now, I need to analyze that further when I got time.

[vlado]

Best to get us a scene to look at. There are a few parts of the V-Ray code that may produce this effect, but I don't know which one happens in your scene.

Best regards,
Vlado

[Art48]

Just sent an eMail to you, Vlado, containing the download link. ("User: Art48; Thread: RAM unload after render taking extremely long")

[vlado]

I got the scene thanks! I guess part of the problem is that it does take a lot of memory to render to begin with; I'm wondering if there's a way to make that better first.

How much RAM do you have in your machine?

Best regards,
Vlado

[Art48]

I just rendered this scene, and I have 64GB RAM installed, and the final scene when rendering was at about 55 GB (that is total ram consumption according to the task manager), so there's still plenty of room.
I know stuff canbe optimized, but I got no time for that, and RAM is there to use it

[vlado]

Yeah, however I don't have 64 GB So I've got no choice but to optimize.

If I had to guess though, I think the slow release comes from the displacement, but I need to confirm it.

Best regards,
Vlado

[Art48]

Oh, alright ^^
Anyways it would be awesome to have this fixed somehow since it doesn't allow for a very interactive workflow, and displacement rocks and we use it often

[Macker]

It's definitely a displacement issue in my scenes.

[Vizioen]

I've experienced my share of very slow RAM unloads too, with other projects and as far as I remember also used displacement. I also wondered why RAM was so slow to unload, can't it be just 'cleared' or 'deleted' or something at render end.