GPU Power!

[glorybound]

Thanks to Chaos support, we figured out some things with GPU rendering for my exterior scenes. These rendered in 4 hours on my CPU's and 30 minutes on my GPU's.

[trick]

What are these things?

[glorybound]

I am sure they'll show up as defaults in previous releases.

Following up on our call on Friday, here are the settings that I recommend you to use for your projects,

• V-Ray tab, Use the CUDA engine
• V-Ray tab, Set Sampler to Progressive
• V-Ray tab, Frame Buffer section. Set Post Effects rate to 0
• Performance tab, Textures mode should be set to Full-Size, and Check Use System Memory for Textures option. No need for Compressed Textures with new V-Ray builds
• Performance tab, Uncheck the C++/CPU device
• Try to use the least amount of render elements. This affects performance considerably

Furthermore, adding a second 4090 to your workstation will be very helpful because you will move your rendering to a dedicated GPU. Keep in mind that 3Ds Max takes a big chunk of performance and memory from the GPU connected to your monitors. Please check my thread here for the relevant settings after installing your second GPU. You will use a single GPU for rendering and the other GPU for 3Ds Max and monitors.

[DanSHP]

CUDA? Seems much slower usually for me.
Post rate to 0? I thought you'd want this higher?

How do you find IPR and TTFP? This is the deal breaker for me. It's just too slow to update/refresh on large medium scenes.

I switched back to CPU recently and it's just so much better and it looks better. Sure rendering a final image takes longer, but I can run it over night. I've ran a few jobs in Corona recently and IPR is faster to update/refresh than Vray CPU. Also max can autosave when running Corona IR, Vray still can't....

So for me, it's CPU Vray or Corona. I've spent a lot of time in Vantage too with great success but quality isn't quite there yet.

[glorybound]

I was told that CUDA (out of core) will be the default in future updates, and for post rate, I was told 0. The deal breaker for me started and cancel times, but with the texture mode changed, that has changed. I am also using a text version, so maybe there were other things optimized.

[trick]

Good to know the rules! I currently have a Gigabyte RTX4090 Waterforce combined with a (single slot) RTX A4000. It looks like all is quite a bit smoother working in Max with interactive rendering on the RTX4090 while keeping the box quiet and cool and not that "hungry" , which was my second intention.

[Muhammed_Hamed]

CUDA? Seems much slower usually for me.

With recent drivers and V-Ray builds, CUDA catches up with RTX in performance for most scenes. Plus CUDA uses less GPU memory, around 25% on average than RTX

Post rate to 0? I thought you'd want this higher?

For final rendering it should be set to 0, so Lens effects or the denoiser doesn't interrupt rendering.
For IPR, you could use higher values with the denoiser, I think it is set internally to 100

How do you find IPR and TTFP? This is the deal breaker for me. It's just too slow to update/refresh on large medium scenes.

We have a big change in our internal builds, TTFP is 2 to 5x faster than before. In many cases as fast as the standard V-Ray CPU and sometimes faster. In Bobby's case, switching from Compressed textures to Out Of Core improved his TTFP significantly. Now, we are trying to improve the performance of texture compression on TTFP
On another note, with nightly builds for 6.2 this should be improved as well, and CUDA engine works better usually

I've ran a few jobs in Corona recently and IPR is faster to update/refresh than Vray CPU

Try with my settings here, with high-end GPUs like the 3090 or 4090 V-Ray GPU has much better performance. We will update these settings in the upcoming version.

Best,
Muhammed

[Muhammed_Hamed]

Good to know the rules! I currently have a Gigabyte RTX4090 Waterforce combined with a (single slot) RTX A4000. It looks like all is quite a bit smoother working in Max with interactive rendering on the RTX4090 while keeping the box quiet and cool and not that "hungry" , which was my second intention.

Glad to hear!
Make sure to use a high value for IPR Rays Per Pixel, 4 should work well, and IPR Ray Bundle Size of 512 to push your GPU usage as high as possible. More about this here
I have a second guide on performance here as well, it could be helpful

Best,
Muhammed

[Muhammed_Hamed]

glorybound

Thanks for sharing!
Looks great!

Best,
Muhammed

[trick]

Glad to hear!...

Thanks for the hints. The box is still being tested thoroughly waiting to be my daily workhorse, so I will surely experiment with your settings.

[DanSHP]

glorybound

Thanks for sharing!
Looks great!

Best,
Muhammed

Muhammed_Hamed Would you have some free time to run through a scene as you did with Glorybound?

[fixeighted]

On the docs page you linked Muhammed, there are the suggested presets for high end/Mid cards etc.
Are there similarly tested suggested settings for final renders?
I only have a 2080ti and although the above info has me updated somewhat, I only see my GPU useage for final at around 5% using the defaults, which seems wrong, unless
I'm misunderstanding something or looking at some wrong data.

[Muhammed_Hamed]

Muhammed_Hamed Would you have some free time to run through a scene as you did with Glorybound?

Sure
Send me a message on forums or an Email, muhammed.hamed.ext@chaos.com

[Muhammed_Hamed]

On the docs page you linked Muhammed, there are the suggested presets for high end/Mid cards etc.
Are there similarly tested suggested settings for final renders?
I only have a 2080ti and although the above info has me updated somewhat, I only see my GPU useage for final at around 5% using the defaults, which seems wrong, unless
I'm misunderstanding something or looking at some wrong data.

You need to set Post Effects rate to 0 and use progressive mode
Do you see 5% GPU usage in GPU-Z?

Also check for the warning: Num Samples Per Thread reduced to XXX, rendering might be slower. In case you are close to the memory ceiling on your GPU

The ray bundle size and rays per pixel are only useful with IPR, the values for production rendering shouldn't be changed

Best,
Muhammed

[fixeighted]

Ok thanks for that.
I was looking at Task Manager for the usage but am now looking at GPU-Z and it's getting to 100%, so I guess all is well.

Mainly I think it's the 'use system memory for textures' that has changed the game for me personally, as that was what was scuppering every
attempt at using GPU previously.