V-Ray GPU not releasing memory

[francomanko]

Hi, heres a link to scene memhold.zip

https://www.dropbox.com/scl/fo/llajdu97u0wz41gxg715n/ALwbwENT2C_yOs4oNtctWpE?rlkey=jsv046idqdu1eak8w8h1 srz5k&st=7y11lh6q&dl=0

although its the same issue as the scene i sent you a while ago...ever since vray 7

Im using :

win 11
vray 7.0.0.05 gpu (nighlty)
nvidia 566.14 studio
rendering in cuda.

so I just tested again to make sure with 2 3dsmax open.

Pre render ram on gpu : 1286
Ram usage on 1st scene whilst rendering : 7998
Ram usage after render stopped : 5400

Ram usage on 2nd scene whilst rendering : 12116
Ram usage after 2nd render stopped : 9518

[francomanko]

(ignore the 'attention required' link at the bottom) I cant seem to be able to edit the post and remove a link.

[Martin.Minev]

Hello francomanko,

We made tests using your scene file, testing with both a single instance of 3ds Max and two instances.
Additionally, we tested with both a nightly build and the official build.
After stopping the scene after rendering, VRAM usage remains higher than it was before the initial render, most likely related to caching.
To confirm that there is no memory leak, you can render and stop the scene multiple times. You’ll notice that the memory usage does not continue to increase with each run.
Here is a screenshot. In this test, we used a higher resolution for your scene.

[francomanko]

hi, thanks for the reply. So I can see that if you restart the render in the same scene it flushes the cache, but the problem is that if I open another instance of max and render in that, without closing the original max, the cache hasnt been flushed so it accumulates. Are you seeing the same thing because i might be getting confused

[Martin.Minev]

Hi francomanko ,

Yes, when running multiple instances of 3ds Max, the cache from both sessions will accumulate.
To avoid high memory usage, it's best to refrain from running a second instance of 3ds Max. Also using other GPU-intensive applications simultaneously will impact the memory.
In some cases, the 3ds Max viewport can use a significant amount of VRAM.

[francomanko]

Doesnt that seem like a bit of a drawback especially when gpu ram is quite limited? Or maybe its just me Would there be a way of implementing a release cache option?

[Muhammed_Hamed]

Doesnt that seem like a bit of a drawback especially when gpu ram is quite limited? Or maybe its just me Would there be a way of implementing a release cache option?

Testing other renderers that can flush VRAM, they are not stable and they are prone to crashing. Having multiple sessions of 3Ds Max open for GPU rendering doesn't seem like a good idea.
This behavior is not new in V-Ray 7 but the cached VRAM might have increased a bit compared to V-Ray 6

Best,
Muhammed