Is it possible to free up VRAM occupied by Karma XPU from past viewport renders without restarting Houdini? Cache Manager can free up some, but sometimes it's not enough if driver is set to fail on "No Working GPU Devices" (insufficient available VRAM). So usually if I perform some viewport renders, I then need to restart Houdini in order to render with USD Render ROP to file, or otherwise the render will fail.

I can live with that, I guess, but having to do this chore is somewhat tedious.

You can restart Karma XPU in the same menu as you see all the renders.

1. Start Karma XPU
2. Switch to OpenGL/Vulkan.
3. Now you should get Restart Karma XPU in the middle of the dropdown menu you see all the different renders.

I'm only on my phone atm, not 100% sure if it's restart Karma XPU. But it's something close.

Thanks Heileif, but the question is about rendering to file (via USD Render ROP), not inside the viewport. So I'm afraid that restarting Karma wouldn't help much.

The problem is that when you work with Houdini for an extended period of time, maybe a few viewport renders in LOPs, then some composition in COPs, things like that, and then want to return to LOPs in order to render to file, there's almost always not enough of VRAM (at least on my GPU). Something accumulates in video memory even if its presence should no longer be required. After restarting the program, USD Render ROP will render the scene without issues.

It's this kind of thing.

ajz3d
Is it possible to free up VRAM occupied by Karma XPU from past viewport renders without restarting Houdini?

XPU should be freeing its data no worries (either when the renderer is closed down, or if it fails). It could be another system is holding onto the VRam (eg OpenCL or Vulakn). We are aware of a GPU memory leak with regards to OpenCL to Vulkan interop. We are wanting to improve this area, so will keep you posted.

Thanks for the feedback, Brian. It's good to hear the issue is known and has your attention.
Looking forward for future updates on this matter.