Hello,

Houdini is lagging quite hard while rendering in the viewport in solaris with karma (cpu as well as xpu)

It feels like karma is using all the cpu resource to it'S max and there is no resource for interface interaction left, but I am not sure about that.
When I look in tutorials about karma viewport rendering everything seems to stay snappy while the tutor is rendering in those videos.

Anybody else having this issue?
I am using a Threadripper Pro 3975wx with 32cores and RTX 3090 + GTX 1080ti on Windows 10

Any help would be great, since I would like to explore Solaris, but like this it's unusable for me.

Cheers, Marco

I found out that it has something to do with the render viewport size. I am using a 4k monitor, when the renderviewport is big, things get laggy, when it's smaller things are getting better. Seems I found a workaround for now, but still not optimal cause of course I would like to work in a bigger renderviewport window.
Any help would still be very nice.

It is possible to reduce the render resolution in the display option for render delegates. Start your render delegate e.g. karma, hit "D" with your mouse over the viewport.

You can then change the image resolution.

Hi David, thx for the tip.
This is also seems like a workaround that improves the performance a bit Similar to what I do at the moment:
Things work snappy when I make the Renderwindow quite small (about 1/4 of my 4k monitor).
I don't have this issue when I make interactive renderings with mantra or redshift. There things stay perfectly snappy while rendering in full resolution on one 4k screen interactively.

Strangely I just found out that things run better on my second, much slower machine (a 2012 Mac Pro with dual 1080p monitors).
So maybe this faulty performance only occurs on certain type of setup combinations?

My main workstation setup is a threadripper pro 32core with rtx 3090 + gtx 1080ti, dual 4k monitor setup, 256GB ram, windows 10 pro.

Best, Marco