Peculiar performance problem with Win11/VmWare Fusion on M1 iMac

[neilw]

Recently I created a Win11 ARM VM on VMWare Fusion, for the sole purpose of running Paint.net. It works, but I am experiencing a strange performance issue.

Basically, the mouse response is smooth when I'm in the toolbar and menu area at the top of the screen. But once I move the mouse below that, response becomes terrible, like maybe 5-10 FPS at most. It doesn't seem to me like just moving the mouse around within the drawing area should be such a strenuous operation that is slows down so much. Is this explainable and/or fixable?

 

[izzy0242mr]

Recently I created a Win11 ARM VM on VMWare Fusion, for the sole purpose of running Paint.net. It works, but I am experiencing a strange performance issue.

Basically, the mouse response is smooth when I'm in the toolbar and menu area at the top of the screen. But once I move the mouse below that, response becomes terrible, like maybe 5-10 FPS at most. It doesn't seem to me like just moving the mouse around within the drawing area should be such a strenuous operation that is slows down so much. Is this explainable and/or fixable?

View attachment 2357015

I don't have a solution but can confirm the same behavior on a similar setup (Win11 Arm on VMWare and M1 Pro).

Interestingly, the only way I noticed the framerates don't drop is when I'm using the pencil tool. Seems very smooth. But everything else, like the paintbrush tool, or selectors, all lag a lot like you describe. Unfortunately I don't know if there's a fix.

 

[neilw]

Well I'm glad to know I'm not crazy. It's a weird problem.

I think I'll head to the Paint.net forums and see if anyone has a clue what's going on.

 

[neilw]

For what it's worth: I recently upgrade to an M3 iMac and it seems like this particular issue is mostly resolved. I can't tell if mouse performance in the drawing area is *completely* smooth, but it's close enough that I don't think I need to worry about it.

Overall, for non-GPU tasks I find the machine to be only slightly faster than the old one, barely noticeable. But I had been crossing my fingers that it would fix this issue for me, and I am pleasantly relieved that it has.

(this was not the reason I upgraded in case anyone is wondering)

 

[mattspace]

I recall something in the VMWare forums recently to the effect that Fusion doesn't pass any GPU acceleration through at all. Speculation - the painting app is drawing the canvas viewport area directly to the GPU - ie that part of the screen is direct GPU output. I'd be interested to know if the slow mouse response happens in the layers palette - if you made that really big to see if it's a crude divisor between the top and bottom, or if it's the canvas viewport specifically.

 

[neilw]

I recall something in the VMWare forums recently to the effect that Fusion doesn't pass any GPU acceleration through at all. Speculation - the painting app is drawing the canvas viewport area directly to the GPU - ie that part of the screen is direct GPU output.

That's a pretty good hypothesis.

I'd be interested to know if the slow mouse response happens in the layers palette - if you made that really big to see if it's a crude divisor between the top and bottom, or if it's the canvas viewport specifically.

I will try that, although things seem pretty zippy on the M3 so I don't know if I'll be able to draw any good conclusions.