Josh what I see in the posted image is that there is no Profile and it is being converted from PNG to TIF with Keep Color Profile selected. It doesn’t make sense maybe the app should pick up on that.
So it’s not just me. I noticed the same thing with some images. It happens only at 6x scaling and when using GPU. Using the CPU doesn’t seem to add this grain. Also, 4x scale and lower doesn’t seem to produce this grain even with GPU. I will try sending some samples.
Also after some further testing, it seems that using GPU adds alot more grain than CPU, but if you zoom in very closely, the grain is also present with the CPU (examples in the folder):
As a sidenote- the quality using CPU upscale is slightly better than using the GPU (in my Case GTX 1060, 6GB, latest NV driver as of march 28).
The cpu upscale removes Aliasing/combing artefacts better, which the GPU upscale doesnt do to the same degree and the CPU upscales some small detail better. The AI using the CPU seems to be slightly “smarter” than using the GPU, but process is quite a bit faster using the GPU. I was using the enhancements-> Remove Blur “high” and Suppress Noise “high”. And so after some testing, for the best quality possible, the CPU seems to be the better choice if processing time is not a big factor.
You can check the examples in the linked folder and compare them zooming in to original size.
I can confirm the same issue with Nvidia 970 (4 GB) of VRAM - the effect (pattern) changes when you change amount of ram usage in the settings. Also preview is not accurate - on finished images the sharpening is not as strong as in the preview. CPU algorithm seams to work better and the inaccuracy is less noticeable, but it is still visible.
I think that the question is about vram (video ram) - It makes difference - the pattern is more visible with lower vram settings but its obvious even on high.