We've just finished a very high resolution project (24K x 12K) using Redshift in standard Houdini. We are now investigating starting to move to Solaris/USD and whether we can use Karma instead of Redshift.

I'm running some very basic tests and already hitting an issue with even attempting to render at that resolution, as well as significantly slower render times. I'm testing a very basic scene:

- HDRI dome light
- spherical camera
- various resolutions (4K, 8K, 12K, 24K)

My benchmarks (on a 4080 super) for this scene using Redshift in a standard (non-Solaris) way are as follows:

4K
- 1.7 seconds

8K
- 5.5 seconds

12K
- 9.3 seconds

24K
- 38.3 seconds

Using KarmaXPU in Solaris:

4K
- 6 seconds

8K
- 25 seconds

12K
- 51 seconds

24K
- WON'T RENDER

First up, I'm surprised that there is such a difference in render time with such a simple scene. This is just with one primary sample on Karma, but perhaps I'm missing some really obvious render settings which should bring this down. But no matter what I try, trying to render 24K just totally crashes every time. Is there just a hard resolution limit with Karma?

id love to know more on this too. as we always supply our finals at around 17,000pixels. and have been using RS and vray to do this. on 3090 x2 its fine.

havent tested karma at those res's yet myself, but would like to know if theres any optimizations to get there!