RTX 3090 not used with build from latest source

[Former user]

Hi Matt, I wonder why my brandnew RTX 3090 GPU currently is not used during rendering. I am building from source, because I had the Nvidia hangups that were mentioned in the other issue. Now with the build from source, it works nicely. OpenCL is checked and the right GPU is checked in the final render dialog, but when I look at the task-manager, the GPU usage stays at 2% during rendering. I am using VC19, the build is x64, Release. Please let me know if I can add some logs or whatever might be helpful. Thanks, Christian

[christian schneider]

Uh very sorry! That was me who just created the issue, I was not logged in.. Weird that it was even possible to create an issue

[Matt Feemster]

I wouldn’t worry too much about the stated GPU usage. I would instead do this test:

First, for the interactive renderer, select the setttings dialog. This is NOT the final render dialog. Select your gpu from the table. If you want extra optimization, select Use Shared Texture. Click ok. See if the main window uses your gpu now. You’ll know because if you select cpu, you’ll see it render much slower. Select CL on the toolbar again, and it should switch back to the gpu and you’ll see it speed up again.

Let’s at least verify this works in the interactive renderer first.

[christian schneider]

Thank you very much for your quick reply. You are right, when turning off OpenCL it takes forever . Sorry, I could have checked that. I was confused because when playing a game Windows task manager showed 95% usage, and with Fractorium virutally 0, 2% at most. You can close this issue, of course. I have to add that one of my main motivations to buy such an insane graphic card was Fractorium and not the games .

[Matt Feemster]

Awesome, I am glad to hear my project motivated you to spend the big bucks on a card! We will be releasing a new version within the next month or so with a few bug fixes and some features. But since you are building from scratch, you already have it.

As for the numbers on the task manager, I am not sure what it’s measuring when it’s giving a gpu usage reading. My hunch is that it’s measuring the usage of 3D or video decoding hardware on the card, not the parts that OpenCL uses. You might try using a different diagnostic tool to determine card usage. Maybe Nvidia supplies one or perhaps a third party does?

For my own information, how did you figure out how to build everything with Qt and such? Were you experienced with Qt before? Did you use the build instructions on this project page?

Also, don’t forget to consult fractorium.com for documentation. It covers every part of the program, but it does not tell you how to make good art. That last part is “left as an exercise for the reader”