[runjake]

I don’t notice the slightest decrease in speed or any benchmark going from native 1440p to 1440p hidpi at 4K.

If there is a speed decrease, I can’t notice it on an M1.

I’ve seen a lot of people parrot this claim or claim it renders awfully but have yet to experience any evidence. On the contrary, it’s been glorious.

Edit: if you do 1440p scaling on a 4K on macOS make damned sure you select “1440p (Hi-DPI)” other you get a pixelated mess.

[lucumo]

Maybe the M1s are better. I have a 2019 MacBook Pro. And two external screens, maybe that makes a difference. It was especially bad after upgrading to Monterey.

I don't "parrot" the claim. I've experienced the problem. It's day and night. After installing Monterey I couldn't run MS Teams on the external monitors anymore. It more or less locked up and I couldn't move the window back to the laptop screen. This was repeatable.

The whole problem went away when I selected 1440p (the "low resolution" one). It's fugly, but at least I can actually use my other monitors.

[secureleaf]

I also have the 2019 MacBook Pro and it's been a dumpster fire. I'm running 3x 4K monitors and it's completely unusable with the dedicated GPU (the 5500M).

I spent months trying everything I could think of: downgrading to Catalina, turning off transparency/shadows, running as few background services as possible, and not using scaling at all (which was the most effective solution). And this was only with 2x 4K monitors; I added a 3rd more recently.

Nothing worked. Thermal throttling and insufficient sustained power were two problems I was able to identify (the 96W adapter is not sufficient for the system's peak power load, so it uses the battery to get over 96W of draw).

Eventually, I broke down and bought an eGPU (Blackmagic eGPU) which solved the problem. For about ~$700, I'm now able to use my machine without a hiccup. Not a great or affordable solution, but it has made my $3,100 machine usable again.

[runjake]

I have an i9 2019 MBP 16” at work and also don’t notice a slow down when I bring it home. Maybe it’s a GPU bug?

I’m pretty sure my i9 model has the lower end 5300M.

Another question: what are you using to connect the monitor to your laptop? USB-C to DisplayPort, here. I formerly used HDMI off of a USB-C hub but it was a bummer.

[ENGNR]

Myself and my cofounder can reproduce the exact same issue every time with each of our MBP 2019 5500’s. Another team member with a 5400 running the exact same dev environment as me has never had the issue, so there’s something funky on that model.

It’s pretty bad the Apple still denies any issue, not being able to use an external monitor at all through covid suuuuucked