Daz only allocate 2Gb whatever the scene

Zelrish

So, I noticed in my logs after failing to render a scene today that every render I have een doing apparently only allocates 2GB of VRAM...

2023-02-08 21:58:42.434 Iray [INFO] - IRAY:RENDER ::   1.7   IRAY   rend info : CUDA device 0 (NVIDIA GeForce RTX 3090): Scene processed in 0.107s
2023-02-08 21:58:42.435 Iray [INFO] - IRAY:RENDER ::   1.8   IRAY   rend info : CUDA device 0 (NVIDIA GeForce RTX 3090): Allocated 18.296 MiB for frame buffer
2023-02-08 21:58:42.435 Iray [INFO] - IRAY:RENDER ::   1.7   IRAY   rend info : CUDA device 0 (NVIDIA GeForce RTX 3090): Allocated 1.906 GiB of work space (2048k active samples in 0.000s)

I have 24GB of VRAM, I don't understand why I cannot render a simple scene of 1 character with Fiber mesh hair... (that's what I tried to do today)

I keep getting a ram allocation error as soon as I use filament hairs

The iray preview has no problem whatsoever

 

Richard Haseltine

It's probably failing at the next step, though it should still return an error. Of course you may be running out of system memory as the scene is prepared for Iray. Strand-based hair can be very greedy, especially if it is using geometry rather than Iray curves - set the number of segment to 0 and see if that helps it fit, if not try reducing the density.

PerttiA

The newer DS no longer shows the amount of VRAM it uses for geometry and textures, DS 4.15 does.

barbult

Richard Haseltine said:

It's probably failing at the next step, though it should still return an error. Of course you may be running out of system memory as the scene is prepared for Iray. Strand-based hair can be very greedy, especially if it is using geometry rather than Iray curves - set the number of segment to 0 and see if that helps it fit, if not try reducing the density.

Do you mean set Line Tessellation to 0?

Zelrish

I'm not home anymore to give the proper log entry of the problem, but it said something the lines of : failed to allocate 200MB out of 21GB blabla

And then a list of other fails in memory allocation

I cannot tell if they were RAM or VRAM actually. And in terms of RAM, there was something like 20GB free at the time of render.

 

After like 8 or 10 failed render and stopping Daz process everytime to change line tesselation and other potentially guilty parameters, it started rendering again.

But I'm not sure why at all. It used so very little VRAM btw when successfully rendering...

Originally the tesselation was at 3, I dropped it to 1 but It didn't help right away. 

I think it started rendering because I removed stuff from the scene (and by that, I mean, 2 or 3 dforce simulated dresses that where hidden). I'm just really unsure if daz event tries to use all the ressources at hand. I wish I could confirm it or that the log files had more info in it.

PerttiA

As I said, the newer DS does not show how much VRAM on the GPU is used during rendering, one has to use other programs to check. The best would ne to use GPU-Z, it is simple and shows the needed information without having to make any changes to the settings.

https://www.techpowerup.com/gpuz/
 

Richard Haseltine

barbult said:

Richard Haseltine said:

It's probably failing at the next step, though it should still return an error. Of course you may be running out of system memory as the scene is prepared for Iray. Strand-based hair can be very greedy, especially if it is using geometry rather than Iray curves - set the number of segment to 0 and see if that helps it fit, if not try reducing the density.

Do you mean set Line Tessellation to 0?

Yes, I had a nasty feeling that was wrong as I wrote it. Sorry.

Zelrish

For some reasons... it is now working. Also with rendering tesselationn back to 3

I simply don't understand this software and it's limitations.

More infos in the log file would be welcome though

alliance4g63

I'm running across the same issues. I will IRAY preview at 6.5g, render, and VRAM spikes to 7.8 or more. I've never had this issue before and is making rendering very frustrating. 
 

Im not sure what changed. I've loaded basic models and the  spike still happens. I've used all my usual tricks(scene optimizer, instances, etc,) yet I can barely use one HD model with a low poly environment. I saw another thread with a similar issue so I wonder if it is a recent driver or update. Not sure. Please help. 

Richard Haseltine

The Iray Draw style and the final render do not use exactly the same settings - for example, the drawstyle uses the Vieport division level for SubDed mesh, not the full Render division level.