Hello,
I just can’t find the RTX / CUDA switch in the settings tab in Vray GPU 73004.
I’ve search in the chaos docs and no mention of it.
You still can select your devices in perf. tab but no hard switch anymore ?
Thanks for the help,
Nicolas
The device selection in the performance tab is now the switch.
Hi Aleksandar,
Thanks for the fast answer
Few more question then :
- What happen when nothing is checked ?
- What happen when everything is checked ?
- Is the box “rendering” is the only one who activate the selection or does the “denoising” box activate it too ?
- How to I control in wich mode I am about to render ?
- How do that apply for the past project ? What happened when RTX was previously checked? Will version 73004 automatically check the right device boxes for us, or do we need to manually update all our old scenes using the new selection mode?
I find the new selection mod a bit confusing vs the old one.
Thanks again for your time and your answer
I think it automatically searches for available cards (from what I tested).
All selected cards will be used for rendering/denoising?
Those checkboxes just tell V-Ray which card to do what. They are independent if that’s your question - you can use a certain card only for rendering or only for denoising.
As I already mentioned, that is done through the CUDA/RTX “menus”. Whichever mode is selected will be the one used.
It is based on the host app version of V-Ray (or STD or AppSDK), not project-based.
For example, each V-Ray for 3ds Max 20XX has its own Device Selection tool (located here: "C:\ProgramData\Autodesk\ApplicationPlugins\VRay3dsMax2026\bin\vray_gpu_device_select.exe"). What you see in the host app UI is basically a mirror of the tool, whose job is to set some environment variables.
When you open an old project on a new 3ds Max, the selected GPUs will be from what you’ve set on that particular V-Ray 3ds Max.
Some additional info here.
Okay, thanks for the replies.
I may have misunderstood your first reply, so I assumed that selecting graphics cards by checking them in the CUDA/RTX menu was what allowed you to switch between CUDA and RTX mode and vice versa.
But now I get the impression that selecting the CUDA tab or the RTX tab is what defines the rendering mode?
Because I don’t see any other way to select one mode or the other in the CUDA/RTX menu
I want to force my render in RTX mode but i’m not sure I am doing it right with the new UI since switching tab doesn’t seems to change anything (the log is only triggered by checking cards or unchecking them)
I might do thing the wrong way.
Thanks again,
Nicolas
Exactly.
Start rendering and check the log in the VFB to confirm. If it says “Querying for OptiX Devices…” it is RTX; if it says “Querying for CUDA devices…” it is CUDA.
Okay, I get it.
I’ll learn how to check it in the VFB
It’s not very intuitive, if I may offer some user feedback.
It’s hard to tell at first glance that selecting the tab defines the rendering mode:
-
Because everything is located in the “Render devices select” section, and there’s no mention here of the rendering engine mode, only the hardware. The old version was clear with the “Engine select”
-
Because selecting a tab doesn’t provide clear user feedback that we’ve changed the technology (unlike a checkbox dialog, which inherently implies that it’s either checked or unchecked). Here, the tabs seem to be just a list of hardware settings in case we choose one or the other, but not that we are actually selecting it.
-
Because that has never been the way to select and confirm an option in the UI interface in the history of V-Ray for 3ds Max (as far as I know and use Vray)
Thanks,
Nicolas
You got me wrong. No need to confirm anything. The thing I said about checking the log is just for you to confirm to yourself that selecting the tab equals selecting the engine.
Otherwise, I think that before the checkbox option, the UI to change between CUDA and RTX was similar to the current one.
“You got me wrong. No need to confirm anything. The thing I said about checking the log is just for you to confirm to yourself that selecting the tab equals selecting the engine.”
No, no worries, it was clear 100%. I’ve just never had to confirm before and know I can when I need now.
“Otherwise, I think that before the checkbox option, the UI to change between CUDA and RTX was similar to the current one.”
Not sure to follow your point here.
To switch from rendering with CUDA or with RTX :
In 72008 there is a checkbox in “GPU Engine select” sub category “Settings”
In 73004 there no checkbox and no “GPU Engine select” anymore anywhere and a new TAB selection but this time in sub category “Perf”
It’s in a new VRAY tab, not in the old one,
It’s in a different sub section of this tab with a different naming,
It’s not by checking a box anymore but buy selcting a tab.
Again, maybe I’m not explaining clearly what I didn’t understand, or maybe I’m not looking at the right things, but this is 100% different way of selecting CUDA or RTX between the two versions.
Okay, it doesn’t matter how it was or wasn’t. Just select the CUDA/RTX tab according to your needs, and you’re good to go.