Curious Memory Footprint During Render

mambanegra

So, I just noticed that DS gobbles up a ton of RAM when the render begins (in the example I'm currently using, it was a total of almost 8 gigabytes). But, by 89%, the RAM use listed in Task Manager is under 1gigabyte. That seems counter to my understanding of how DS would render the image (i.e. it refines the image as more and more iterations are completed, as opposed to early Poser renderers that rendered an entire chunk one at a time and then moved on.

The render in question is fairly minimal. 1 G3F, some clothes and hair, a bed and a bunch of cube primatives made to look like she just finished shopping (weighted iray shaders on those cubes). Any way, I'm just curious if anyone knows what that initial grab of RAM was all about and how DS got away of releasing it over time. I wasn't watching when istarted but long enough to make sure it wasn't going to crash. The reason I was watching in the first place was because the same render was killed by windows, presumably due to running out of RAM. It's total usage was just over 8 gigs last night, but wasn't terribly different from the max that I saw this morning before going on about my business. 

Wallace3D

From what I have seen DS will preload all the Geometry info and the textures (2MB - 4MB each texture depending on who made them) 

so if you have G3M with subdivision set to 2 then it will require more ram VS Base resolution plus each texture on the skins diffuse,glossy,bump,normal etc

 

it all adds up pretty fast!

mambanegra

But why did it drop to a tiny fraction during the actual render. It had started rendering before I quit watching and was still sitting at over 7 gigabytes. However, when I checked in nearly an hour later, it had dropped to under 1 gig. I don't know when it dropped, but it appeared to be gradually decreasing it's memory footprint. At least, according to what I was seeing in task manager. I'm normally a mac user, so I'm kinda ignorant about some things, so it's quite possible that task manager's reporting isn't what I think it is. 

mikael-aronsson

Depends on what you render with I would think, with iray it needs to load lots of stuff into RAM and then send it over to the GPU, so it sounds logical that it would use lots of memory to start the renderer and then it would lower it (you do not see the memory used by the GPU in task manager).

The "refinement" process does not use any more RAM with more iterations, the framebuffer is the same size.

But I would also think it is a bit complex to figure out, you have the DS application that use memory, then you have the iray renderer dll that will use memory also, and it is possible things are duplicated because one thing needed in DS may have to be allocated again inside the iray renderer and then comes the GPU into play so it's not an easy thing to figure out, on one side you have to iray renderer and on the other side you have the DS application and UI and viewports.