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Why is nobody talking about how ProMotion just does not work as intended?

beardev said:
Xcode additional tools comes with Quartz Debug, which has a framemeter that will show the current fps of the screen, but it's a bit hard to tell exact numbers because it looks like it's doing some kind of smoothing or averaging.

Using it on 12.1 beta 2, I get these readings, between readings I let the meter drop back to idle.

idle: around ~30fps.
scrolling in safari while keeping fingers on the trackpad: shoots up to ~110fps after a few seconds, stays around there.
small inertial scroll flick in safari: shoots up to ~75fps after about a second.
large inertial scroll flick in safari: shoots up to ~90fps after a few seconds.
dragging the scrollbar in safari: ~65 fps, fairly constant.
spamming quick inertial scroll flicks in safari indefinitely: goes to ~100 fps after a few seconds and stays there.

It's hard to say too much with this because of the potential averaging going on, but it looks like it's probably ramping up the refresh rate too slowly and dropping it down too aggressively. Also, even when the Framemeter is showing 110+ fps consistently for a long period of time (eliminating the possibility of averaging being a problem) it still looks choppy to me.

My guess is in addition to the aggressive rampdown there's also an issue where frames aren't being rendered in sync with the display which is causing bad frame pacing, where you're getting ~100+ fps on average, but the time between frames is inconsistent causing what looks like little lag spikes or choppiness.

Something else that's interesting: Quartz Debug lets you disable Vsync. If I do this, scrolling (especially inertial scrolling) behaves much better, and the framemeter displays 160+ fps when scrolling in Safari at all times. It still has some choppiness to it, which I expect when disabling vsync, but the fact that it behaves so much better I think is good evidence that the problem is their sync implementation with ProMotion.
Click to expand...

Thank you. I had a feeling it was due to frame pacing/v sync. Love seeing people who know what they're talking about on here.
 
Of course it's about the sync which doesn't match the applications refresh rate. The blurbuster ufo test is showing a lot stuttering warnings.

Someone who has still a mbp 2021 can do this test:

www.testufo.com

TestUFO: Frame Skipping Checker

TestUFO: Frame Skipping Checker
www.testufo.com www.testufo.com

I wouldn't wonder if there is frame skipping.
 
I
beardev said:
Xcode additional tools comes with Quartz Debug, which has a framemeter that will show the current fps of the screen, but it's a bit hard to tell exact numbers because it looks like it's doing some kind of smoothing or averaging.

Using it on 12.1 beta 2, I get these readings, between readings I let the meter drop back to idle.

idle: around ~30fps.
scrolling in safari while keeping fingers on the trackpad: shoots up to ~110fps after a few seconds, stays around there.
small inertial scroll flick in safari: shoots up to ~75fps after about a second.
large inertial scroll flick in safari: shoots up to ~90fps after a few seconds.
dragging the scrollbar in safari: ~65 fps, fairly constant.
spamming quick inertial scroll flicks in safari indefinitely: goes to ~100 fps after a few seconds and stays there.

It's hard to say too much with this because of the potential averaging going on, but it looks like it's probably ramping up the refresh rate too slowly and dropping it down too aggressively. Also, even when the Framemeter is showing 110+ fps consistently for a long period of time (eliminating the possibility of averaging being a problem) it still looks choppy to me.

My guess is in addition to the aggressive rampdown there's also an issue where frames aren't being rendered in sync with the display which is causing bad frame pacing, where you're getting ~100+ fps on average, but the time between frames is inconsistent causing what looks like little lag spikes or choppiness.

Something else that's interesting: Quartz Debug lets you disable Vsync. If I do this, scrolling (especially inertial scrolling) behaves much better, and the framemeter displays 160+ fps when scrolling in Safari at all times. It still has some choppiness to it, which I expect when disabling vsync, but the fact that it behaves so much better I think is good evidence that the problem is their sync implementation with ProMotion.
Click to expand...
Just don't understand the 75/80/90hz that much,since the refresh rate is either 60 or 120 anyway...you just give less frames/fps,but the display still has to work as hard ,what the hell does that mean.

At least in iphone I can understand that it depends on the "touch event's,and how fast the scrolling execution is done,since RR can be 60/80/120.buf why 90fpsif it needs 120hz anyway
 
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