Rendering dramatically slowed down

linoge8888

I've got a RTX 4090 and I was able to render with Iray at 1 frame per minute (capped at 300 iterations with denoiser). I was extremely satisfied with this, then for some reason I reopened DS and out of nowhere, any rendering method (Iray, viewport) became extremely slow : 1 iteration per second, so 5 min for a frame. I don't understand, I didn't change anything. Whatever the size of the scene is, it remains at 1 iteration/sec. I'm using DS for 4 years now and it's the first time I come across this bug. 

I enabled CPU fallback : it just keeps rendering slowly on the GPU.

I restarted the PC : nothing.

I updated the GPU driver : nothing

DS 4.23

Win 11

GPU RTX 4090 23.9GB

CPU Intel core i9-12900K

128 GB RAM

Here is a glimpse of the logfile I think interesting, but you may need more...

...2024-10-14 17:34:26.005 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Using iray core convergence estimate.2024-10-14 17:34:26.005 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Allocating 1-layer frame buffer2024-10-14 17:34:26.210 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Using batch scheduling, caustic sampler disabled2024-10-14 17:34:26.210 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Initializing local rendering.2024-10-14 17:34:26.278 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : CPU: using 23 cores for rendering2024-10-14 17:34:26.279 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Using OptiX version 8.0.02024-10-14 17:34:26.281 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Initializing OptiX for CUDA device 02024-10-14 17:34:26.511 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Rendering with 2 device(s):2024-10-14 17:34:26.511 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : 	CUDA device 0 (NVIDIA GeForce RTX 4090)2024-10-14 17:34:26.511 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : 	CPU2024-10-14 17:34:26.511 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Rendering...2024-10-14 17:34:26.511 Iray [INFO] - IRAY:RENDER ::   1.10  IRAY   rend progr: CUDA device 0 (NVIDIA GeForce RTX 4090): Processing scene...2024-10-14 17:34:26.511 Iray [INFO] - IRAY:RENDER ::   1.9   IRAY   rend progr: CPU: Processing scene...2024-10-14 17:34:26.511 Iray (Scene Access) : Retrieving geometry2024-10-14 17:34:26.511 Iray [INFO] - IRAY:RENDER ::   1.8   IRAY   rend info : Using Embree 3.13.42024-10-14 17:34:26.511 Iray [INFO] - IRAY:RENDER ::   1.8   IRAY   rend info : Initializing Embree2024-10-14 17:34:26.511 Iray (Scene Access) : Retrieving device geometry2024-10-14 17:34:26.639 Iray (Scene Access) : Retrieving volumes2024-10-14 17:34:26.639 Iray (Scene Access) : Retrieving textures2024-10-14 17:34:27.114 Iray (Scene Access) : Retrieving device textures2024-10-14 17:34:27.114 Iray [INFO] - IRAY:RENDER ::   1.8   IRAY   rend info : Importing lights for motion time 02024-10-14 17:34:27.114 Iray [INFO] - IRAY:RENDER ::   1.8   IRAY   rend info : Initializing light hierarchy.2024-10-14 17:34:27.114 Iray [INFO] - IRAY:RENDER ::   1.8   IRAY   rend info : Light hierarchy initialization took 29.200 us2024-10-14 17:34:27.120 Iray [INFO] - IRAY:RENDER ::   1.9   IRAY   rend info : CPU: Scene processed in 0.609s2024-10-14 17:34:27.252 Iray (Scene Access) : Retrieving flags2024-10-14 17:34:27.252 Iray (Scene Access) : Retrieving device flags2024-10-14 17:34:27.252 Iray (Scene Access) : Retrieving lights2024-10-14 17:34:27.253 Iray (Scene Access) : Retrieving device lights2024-10-14 17:34:27.253 Iray (Scene Access) : Retrieving section objects2024-10-14 17:34:27.253 Iray (Scene Access) : Retrieving device section objects2024-10-14 17:34:27.253 Iray (Scene Access) : Retrieving materials2024-10-14 17:34:27.253 Iray (Scene Access) : Compiling custom code2024-10-14 17:34:27.253 Iray (Scene Access) : Retrieving environment2024-10-14 17:34:27.253 Iray (Scene Access) : Retrieving device environment2024-10-14 17:34:27.255 Iray (Scene Access) : Retrieving backplate2024-10-14 17:34:27.255 Iray (Scene Access) : Retrieving device backplate2024-10-14 17:34:27.255 Iray (Scene Access) : Retrieving decals2024-10-14 17:34:27.255 Iray (Scene Access) : Retrieving device decals2024-10-14 17:34:27.255 Iray (Scene Access) : Retrieving motion transform data2024-10-14 17:34:27.255 Iray (Scene Access) : Retrieving device motion transform data2024-10-14 17:34:27.255 Iray (Scene Access) : Retrieving lens data2024-10-14 17:34:27.255 Iray (Scene Access) : Retrieving device lens data2024-10-14 17:34:27.271 Iray [INFO] - IRAY:RENDER ::   1.6   IRAY   rend info : JIT-linking wavefront kernel in 12.083 ms2024-10-14 17:34:27.277 Iray [INFO] - IRAY:RENDER ::   1.10  IRAY   rend info : CUDA device 0 (NVIDIA GeForce RTX 4090): Scene processed in 0.766s2024-10-14 17:34:27.333 Iray [INFO] - IRAY:RENDER ::   1.10  IRAY   rend info : CUDA device 0 (NVIDIA GeForce RTX 4090): Allocated 1.490 GiB for frame buffer2024-10-14 17:34:27.337 Iray [INFO] - IRAY:RENDER ::   1.10  IRAY   rend info : CUDA device 0 (NVIDIA GeForce RTX 4090): Allocated 2.094 GiB of work space (2048k active samples in 0.003s)2024-10-14 17:34:27.337 Iray [INFO] - IRAY:RENDER ::   1.10  IRAY   rend info : CUDA device 0 (NVIDIA GeForce RTX 4090): Optimizing for cooperative usage (performance could be sacrificed)2024-10-14 17:34:27.389 Iray [INFO] - IRAY:RENDER ::   1.9   IRAY   rend info : CPU: Allocated 1.490 GiB for frame buffer2024-10-14 17:34:28.598 Iray [INFO] - IRAY:RENDER ::   1.10  IRAY   rend info : Allocating 1-layer frame buffer2024-10-14 17:34:29.078 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Received update to 00001 iteration after 2.568 s.2024-10-14 17:34:30.096 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Received update to 00002 iterations after 3.586 s.2024-10-14 17:34:31.424 Iray [INFO] - IRAY:RENDER ::   1.0   IRAY   rend info : Received update to 00003 iterations after 4.914 s....

 

felis

When attaching a log or part of it, please attach it as a text file. Much easier to read.

Try to untick the CPU in your render settings, and see if that imrpoves it.

When you are saying 'size of the scene', are you then talking about output render size?

What happens if you just load a primitive and an HDRI and render that?

linoge8888

I didn't attach the logfile becauyse it's huge but i didn't think about editing it. Doing it right now.

Complex scene with a furnished set and two figures : 1 iteration/sec

1 primitive : almost 2 iterations/sec

CPU fallback unticked : nothing changed 

No mining virus detected by windows defender. The GPU lines in task manager are flat. 

felis

Which GPU driver version are you using?

linoge8888

I was using the previous version, from August 2024. The update to the latest studio version didn't change anything. At all. 

felis

This from your log looks odd 

"2024-10-14 18:22:17.821 [WARNING] :: \src\pluginsource\DzIrayRender\dzneuraymgr.cpp(373): Iray [ERROR] - OPTX:RENDER ::   1.0   OPTX   rend error: input resolution too large, tensor size 4555116544 (max 4294967295)"

But I don't know where it may come from, and the impact.

Else I must admit, I don't have many ideas. I tried a cube with an HDRI and it gave me 150 iterations in less than 3 seconds on a 4070.

You could try to implement the beta and see if that behaves similar. If so, you have to "buy" (0 $) it first, and in DIM in filtering include 'Public Build' (it cannot be installed manually).

linoge8888

So, I've dowloaded beta studio and it kept crashing with my big scene until I lowered the resolution on both figures. Now it's back to the slow pace (1 iteration/sec). But at least for a primitive, it's at the speed of light. Here is the logfile ; it crashed at the last line. 

It's not new : I create a big scene with 3000 frames and it works fine until I restart DS. Then I need to lower some resolutions, but it is the very first time the GPU rendering speed drops that much. It used to be "crash or pass". 

linoge8888

Well, I loaded a previous version of my scene and it seems to work well for now. I'll move on carefully each time I change something on it.