[lucumo]

> MacOS in particular does an excellent job of rendering 2560x1440 to a 4K screen, and the increased DPI over a regular 1440p 27" screen is very noticeable.

MacOS in particular gets amazingly slow when you don't use a 1:1 or 2:1 scaling. I too have have two 27" 4k screens and they made the machine unbearably slow. It got so bad that I now treat them as 1440p screens and let the screens do the scaling. It's not pretty and slightly hazy, but at least the machine is usable.

[BugsJustFindMe]

macOS has secret modes that disable the 8x upscaling dance that happens in this situation. You access them by holding the option key while switching to scaled resolution from native. The text quality is very slightly worse but the performance is very significantly better.

[dijit]

My Mac is unusably slow sometimes. I think this is the reason. I will try using native sizes and see if it improves. Thank you for this tip

[musicale]

There is a strange bug I've seen a couple of times where graphics, even simple things like scrolling a web page, get really slow even though it's supposedly using the GPU. Rebooting or logging out and in again seemed to fix the issue.

Also sometimes the virtual memory subsystem seems to get confused or overcommitted (e.g. after running a bunch of large VMs in VMware) and from that point on everything is just slow, even if you shut down every VM to relieve the memory pressure. It may be related to macOS's use of memory compression.

Then there are various background daemons (mdworker, syspolicyd, photoanalysisd, etc.) that occasionally wake up and decide to eat all of your CPU while simultaneously hammering your file system. The only effective response, short of disabling the offending service (which is much harder than it is on Windows or Linux, due to SIP) seems to be to let them run their course as they decide to scan every file they can find for the 100th time.

And when your laptop heats up, then macOS starts throttling the system via kernel_task processes that appear to be using all of your CPU.

[thebean11]

The new MacBook pros can handle it

[ddek]

Hell, not even the pros.

My work laptop is a 2019 i7 MBP, it struggles with my 4k monitor regardless of scaling. I bought the cheapest mac mini last year to see what the M1 fuss was about, and it has no problem with the 4k screen, even with scaling.

Other OS's? Windows is passable until you start transitioning in and out of full screen. Linux...

[sangnoir]

My Windows games run at higher frame rates at 4k under Linux (Proton) than on Windows natively. I only had to set up the scaling once - just like I had to with Mac OS for the same monitor. Linux display issues are greatly exaggerated, IMO.

[seanw444]

I was gonna say "Linux... what?" I have the least issues with any hardware on Linux compared to other systems. Monitors are no exception. And if something doesn't work out of the box, you have options, rather than just being SOL with other systems.

[runjake]

I think the parent means the new Apple Silicon-based MBPs, not the 2019 models. I may be misreading the way you phrased your comment though.

[pixiemagic]

I think they are saying that even the non-pro M1 machines are significantly better than the previous pro models.

[runjake]

That's what I meant, too. :)

[messe]

I've a 2019 16" MBP that I use for work, and it handles it fine as well; probably due to the discrete GPU kicking in once an external monitor is connected. Likewise, my M1 air sees no issues.

[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