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.

 

[neilw]

Well, I updated VMWare Tools and now my performance is back to crap.

BTW mouse performance is fine in the layers palette.

(I'm now on Fusion Pro 13.5.2, but the performance regression happened while I was still on Player 13.5.1).

UPDATE: I tried turning off 3D acceleration and whaddya know, performance is much better. ¯\_(ツ)_/¯