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?
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
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 
I’ve been having this problem too, but never thought to check the speed of the RAM.
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.
Speed of the RAM wouldn’t be relevant for something like this.
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.
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
Just sent an eMail to you, Vlado, containing the download link. (“User: Art48; Thread: RAM unload after render taking extremely long”)
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
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
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
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
It’s definitely a displacement issue in my scenes.
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.
I’ve wondered that too. It certainly can be, Ctrl+Although+Del end task does it instantly 
(I’m sure there’s more to it than that)
For me that always was a combination of vraydisplacement visible in reflections/ refractions. The whole reason to use vraydisplacement over standard displacement is to get better detail, since geometry is only subdivided on the fly where it is actually visible in the rendered frame and then unloaded again after that buckets are done, sort of like with vrayproxies. But if its visible in refractions, then all of a sudden it needs to load much more geo into ram.
I already asked this before and it seems like the slow unloading is a windows issue and can´t really be fixed.
I asked for an option to simply make the vradisplacement invisible to reflections/Refractions, because most of the time you wouldn´t be able to tell the difference anyway, but just rendering in different passes is messy and tedious…
possibly related to this old issue.. no idea if this is still a problem, didnt use fur for a while.
Why is it then that I can have a 50GB ram scene (with no displacement, size due to image size and very heavy geometry (Grass, trees, etc)) which will unload in a few seconds? I am not a programmer by any means, I just kinda wonder how windows can be the issue when apparently it is capable of unloading it fast under different circumstances.
I had this quite bad a while ago, no displacement (or at least is was disabled in global tab) , but a very large park with lots of a veg, few km’s long. and high res renders, 360’s and a 15k plan.
it was taking as long as the renders to unload. the only thing the saved me in the end was vrimg, and canceling the jobs while waiting to unload.
pc’s had 64gb ram and it wanted more than that.