DAZ3d VRAM Fallback at weird times and how to stop?

[pollenart]

So this is a weird issue.

I use to have a lot of instances of CPU Fallback due to lack of VRAM and other elements which is to be expected on my 3070. Causes being, an over abundance of objects in scene or subdiv5 elements etc etc...

But lately the fallback has been occurring everytime after I finish saving the renders I make. Which of course does that weird thing where the system locks up worse than running a prime95 benchmark and fixing it means ending the daz process.

My question is, is there anyway to fix this? This lockup even occurs on subdiv 2/3 renders even if its just a single model and single hdri. Or am I just fucked due to DAZ Lottery.

I currently use Spectral Rendering/ACESCG for all my renders if that helps.

 

[Majindevil]

hmm i have a much older gpu (geforce 970) but i thik it may be the same problem.
i often encounter it when i am testing a model and experiment with shaders and lighning.

first test render everything is ok vram a as example 80% but after canceling the render and even without changing anything in the scene the vram hits 100% and falls back to cpu.

i checked what the problem could be and watched my vram bevore the first render when its idle and has around 10-15% in use but after a canceled or finished render process the used vram is at around 30-40% so it seems that daz dosnt clear the vram after a finished or canceled render process so even much more vram than i have you could still hit the limit after several renders and get a fallback to cpu.

maybe there is a way to clear the vram after each scene but havent found one only the time consuming method to restart daz and reload the scene for a render process (and this is really a pain with only 4gb)

and this also will cause the slowdown of your system (my rig: 4gb vram + 16gb system ram) its not so bad if 5 or 6 gb goes to the system ram at a fallback but when i remember right the 3070 has around 12gb so if you only run on 16gb system ram like me there isnt much left for daz itself + windows so your pc will run like a potatoe till the system ram has enought recourses again.

 

[pollenart]

Yes I was thinking the app needs a way to flush the cache/usage.. but knowing Daz it'll never be fixed.

The 3070 i have is only 8, but regardless I think its just going to be endless until I buying something with an overkill amount, and even then knowing Daz a 3090 and above will still hit that 24GB limit and fallback either way the next round of nvidia cards that drop I won't be getting anything less than 24GB vram if I still work in Daz.

 

[MissFortune]

Yes I was thinking the app needs a way to flush the cache/usage.. but knowing Daz it'll never be fixed.

The 3070 i have is only 8, but regardless I think its just going to be endless until I buying something with an overkill amount, and even then knowing Daz a 3090 and above will still hit that 24GB limit and fallback either way the next round of nvidia cards that drop I won't be getting anything less than 24GB vram if I still work in Daz.

Rauko actually did a video similar to this topic. How many Genesis 8 Models can you fit on a 3090? 14, which ended up being around 17.4GB of VRAM, iirc. He ran out of 64GB of RAM before he could fit more. Most average users would never run out of VRAM without going overkill like that, imo.

I'm on a 3080 and it still happens to me sometimes. Before every render (I know, it's a hassle), save and restart Daz, should work fine after that. If you'd rather batch render, ManFriday's Render Queue restarts Daz automatically before each new render in the queue, so that might be another option.

 

[pollenart]

Rauko actually did a video similar to this topic. How many Genesis 8 Models can you fit on a 3090? 14, which ended up being around 17.4GB of VRAM, iirc. He ran out of 64GB of RAM before he could fit more. Most average users would never run out of VRAM without going overkill like that, imo.

I'm on a 3080 and it still happens to me sometimes. Before every render (I know, it's a hassle), save and restart Daz, should work fine after that. If you'd rather batch render, ManFriday's Render Queue restarts Daz automatically before each new render in the queue, so that might be another option.

Crazily enough, I just started saving as jpg instead of png and I haven't had it do the fallback since -- knock on wood...

 

[osanaiko]

Crazily enough, I just started saving as jpg instead of png and I haven't had it do the fallback since -- knock on wood...

You can try watching the GPU ram allocation with Resource Monitor.
I've noticed that sometimes it can take a while to give back the ram after completing the render and closing the result image.
Also, do you have the editor viewport type set to Iray during render? if so, try it on a simpler viewport type just before starting to render.
There's also the unfortunately all to likely chance there has been a regression in Daz/Iray library with the latest versions causing PNG image save to fail to clear the memory after it is done.

Also, if you prefer to avoid JPEG and stick with a lossless image format so you have best results from any post-work etc before later conversion to a compressed format like JPEG or WEBP, then you can also try TIFF rather than PNG and see if that makes a difference,