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bill-p

macrumors 68030
Original poster
Jul 23, 2011
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Well, I found out how to do it. This is silly as hell.

1. Enable Develop menu
2. Go to Develop > Experimental Features > disable GPU Process: Canvas Rendering
3. Restart Safari
4. Set display refresh rate to ProMotion
5. Launch testufo.com, notice how the UFOs are scrolling at 60fps
6. Now set display refresh rate to 48Hz, notice how UFOs are scrolling 24fps now (oh ho! So Apple is actually forcibly HALVING refresh rate)
7. Switch Safari to fullscreen and then swap back and forth between the fullscreened Safari window and the desktop
8. If you're lucky, it should now say 48fps
9. Set display refresh rate to 60Hz, testufo should say 60fps now
10. Set display refresh rate to ProMotion, you should get 120fps now
11. Done! Just keep testufo.com as a tab. It seems to take up some resource but it'll keep scrolling at 120fps (note, some pages may still drop frames while scrolling) on all other Safari tabs and windows.
Edit: actually, I don't think I even need to keep testufo.com around anymore. Safari now remains at 120fps even after sleep even when testufo.com is not present. As long as Safari itself has not been closed. Huh...

Screen Shot 2021-11-18 at 1.56.42 PM.png


P.S.: is this confirmation that Apple could enable this at any time and they didn't because... reasons?
 
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Well, I found out how to do it. This is silly as hell.

1. Enable Develop menu
2. Go to Develop > Experimental Features > disable GPU Process: Canvas Rendering
3. Restart Safari
4. Set display refresh rate to ProMotion
5. Launch testufo.com, notice how the UFOs are scrolling at 60fps
6. Now set display refresh rate to 48Hz, notice how UFOs are scrolling 24fps now (oh ho! So Apple is actually forcibly HALVING refresh rate)
7. Switch Safari to fullscreen and then swap back and forth between the fullscreened Safari window and the desktop
8. If you're lucky, it should now say 48fps
9. Set display refresh rate to 60Hz, testufo should say 60fps now
10. Set display refresh rate to ProMotion, you should get 120fps now
11. Done! Just keep testufo.com as a tab. It seems to take up some resource but it'll keep scrolling at 120fps (note, some pages may still drop frames while scrolling) on all other Safari tabs and windows.

View attachment 1913572

P.S.: is this confirmation that Apple could enable this at any time and they didn't because... reasons?
Thanks lol.such weird **** though ..
 
I think this is confirmation that the feature has always been there. Apple is just forcibly disabling it.

I'm guessing that's because there are websites that will stutter while scrolling, so if you have sites that are scrolling at 120fps, and some that are scrolling at like... 69fps, then the experience will be quite jarring.

Then again, forcibly making Safari run at half the frame rate as refresh rate is also not a good idea. Setting to 48Hz means Safari is running at just 24fps and it's very... choppy!
 
I think this is confirmation that the feature has always been there. Apple is just forcibly disabling it.

I'm guessing that's because there are websites that will stutter while scrolling, so if you have sites that are scrolling at 120fps, and some that are scrolling at like... 69fps, then the experience will be quite jarring.

Then again, forcibly making Safari run at half the frame rate as refresh rate is also not a good idea. Setting to 48Hz means Safari is running at just 24fps and it's very... choppy!
Using xcode latest tools,a dev showed that 120hz was indeed here,though not fully exploited.depending on the scrolling behavior ,and whether you fingers would still be on the trackpad,the amount of frames would be greater ,albeit not full 120fps(more like 80-90fps from memory ).still,as the MBP doesn't have anything between 60 and 120hz,the display must be running at the latter .

Yet I have a feeling that apple may be doing it in order to get better battery runtimes.... Since refreshingg at 120fps sucks more battery...but then the display being at 120hz already represents the main major consumption anyway...a bit more GPU would be required for 120fps but that's all
 
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6. Now set display refresh rate to 48Hz, notice how UFOs are scrolling 24fps now (oh ho! So Apple is actually forcibly HALVING refresh rate)

This UFO demo might be interlacing with those settings.

For example, 25 frames per second UK film speed showed on PAL screens at 50hz. 29.97 frames per second in the US was NTSC 60hz.
 
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This UFO demo might be interlacing with those settings.

For example, 25 frames per second UK film speed showed on PAL screens at 50hz. 29.97 frames per second in the US was NTSC 60hz.

I think Apple is simply halving the frame. I just took the camera out to do a comparison to see and there's no interlacing.
 
i made this change but testufo keeps reporting 60 fps... why ?
 
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i made this change but testufo keeps reporting 60 fps... why ?
same to me.
I think i;ve missed something at step 7:
7. Switch Safari to fullscreen and then swap back and forth between the fullscreened Safari window and the desktop

can you detail a bit how to do that switch?
 
same to me.
I think i;ve missed something at step 7:
7. Switch Safari to fullscreen and then swap back and forth between the fullscreened Safari window and the desktop

can you detail a bit how to do that switch?
Yep I'm also struggling with this step, I can't get it to show 48fps at this step
 
i think i've managed to do it...

Screenshot 2021-11-19 at 14.52.45.png


For step 7, i just used the 4 fingers gesture to open Mission Control, then tap on Safari again.
 
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Right, yeah. This is what I had to do:
1) open testufo.com in a new tab
2) Open settings, change refresh rate to 48hz
3) ufo site will say 24fps
4) Put safari in full screen, then user 4 finger gesture to open mission control, then tap the safari icon (not your dock one)
5) restart safari with ufo site open (right click on dock, "quit") then start it up again
6) when it reopens, give it a couple seconds on the ufo site and it'll say 48fps
7) open settings again, change back to promotion
8) Tab back to safari and it'll say 120fps

Closing safari again will revert it back to 60fps
 

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  • Screenshot 2021-11-19 at 13.13.49.png
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Right, yeah. This is what I had to do:
1) open testufo.com in a new tab
2) Open settings, change refresh rate to 48hz
3) ufo site will say 24fps
4) Put safari in full screen, then user 4 finger gesture to open mission control, then tap the safari icon (not your dock one)
5) restart safari with ufo site open (right click on dock, "quit") then start it up again
6) when it reopens, give it a couple seconds on the ufo site and it'll say 48fps
7) open settings again, change back to promotion
8) Tab back to safari and it'll say 120fps

Closing safari again will revert it back to 60fps

These steps work. I'm using external monitor and 4K 144hz scrolling on safari is way smoother. I never close it so this is quite useful. Thank you.
 
Can confirm, this worked great for me on an external display as well!

Disabled Canvas Rendering
Set refresh rate to 60
Restarted Safari and went to testufo
Mission Control to Desktop
Mission Control to Safari
Changed Refresh Rate to 144Hz and it's running at 144hz.
 

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  • CleanShot 2021-11-19 at 09.09.31@2x.png
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After setting the refresh rate to 120hz for Safari (using the above method), i discovered an annoying sttuter when scrolling (if you scroll and then stop for a few seconds it's "laggy" when you start scrolling again- i dont know how to explain). It drives me crazy, so i switched back to 60hz.



Does anyone else encounter this?
 
Doesn't seem to be working on 12.1 Beta (21C5039b).

Another thing I noticed is that the refresh rate on the testufo matches the one under the System Preferences, unlike what has been said here. I guess they have changed something in the latest betas?

Screenshot 2021-11-19 at 22.31.33.png
 
You need to change the refresh rate to ProMotion after that step.
I did, it reverted to 60Hz. My point with the screenshot was that people claim that testufo shows half of the selected refresh rate (so 48 should match 24 on the website), but this does not seem to be the case on the latest beta.
 
I did, it reverted to 60Hz. My point with the screenshot was that people claim that testufo shows half of the selected refresh rate (so 48 should match 24 on the website), but this does not seem to be the case on the latest beta.
I tested it on 12.0.1 so maybe someone on beta could chime in then
 
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All I did was set it to 48, close Safari, restart Safari, set it to ProMotion and that's it. It was 120. None of these complicated hoops required.
Yep that works. It's still not 100% smooth like the iPhone 13 Pro and 12.9 iPad Pro. But... noticeably better than it was. We need a proper fix from Apple.
 
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After setting the refresh rate to 120hz for Safari (using the above method), i discovered an annoying sttuter when scrolling (if you scroll and then stop for a few seconds it's "laggy" when you start scrolling again- i dont know how to explain). It drives me crazy, so i switched back to 60hz.



Does anyone else encounter this?
so i'm the only one who have this issue after setting it to 120hz?:rolleyes:
 
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