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Sarah Hamilton

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Oct 19, 2021
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I've already got a 4K display it is the Dell S2817Q and when I select the default 4K resolution, all the UI elements and font sizes are too small. I have to down scale to 2560x1440. I take it theres no point in getting a 4K display with MacOS as it doesn't work? Sorry I am new to Mac computers.
 
The "Looks like 2560x1440" mode in macOS is actually a 5120x2880 mode scaled down to 4K so the text will appear smoother than it would on a lower resolution 1440p display. Basically, 4K is a poor man's 5K or 6K display. They can all do "Looks like 2560x1440" or "Looks like 3008x1692" but each increase in display pixels will make each mode look slightly better. Of course, "Looks like 2560x1440" will look best on a 5K display and "Looks like 3008x1692" will look best on a 6K display.
 
The "Looks like 2560x1440" mode in macOS is actually a 5120x2880 mode scaled down to 4K so the text will appear smoother than it would on a lower resolution 1440p display. Basically, 4K is a poor man's 5K or 6K display. They can all do "Looks like 2560x1440" or "Looks like 3008x1692" but each increase in display pixels will make each mode look slightly better. Of course, "Looks like 2560x1440" will look best on a 5K display and "Looks like 3008x1692" will look best on a 6K display.
I am that poorwoman lol! I have the Dell s2817Q, do you think I am better off buying a qhd/2k display rather than downscaling to 2560x1440 on a 4k display?
 
I am that poorwoman lol! I have the Dell s2817Q, do you think I am better off buying a qhd/2k display rather than downscaling to 2560x1440 on a 4k display?
QHD or 2K is 2560x1440. That's less pixels than 4K. 4K is better and is much less expensive than 5K or 6K. You only want QHD for gaming with higher refresh rates.

You're not downscaling to 2560x1440 on the 4K display (or not upscaling 2560x1440 to 4K). You're downscaling from 5K to 4K. There's a difference. The Mac's Retina or HiDPI or "Looks like" modes draw objects and text twice as high and twice as tall as they would be on a QHD screen - everything has 4 times as many pixels so they are smoother and have more detail.

I like 4K just fine. None of those pesky 5K/6K connection issues (requiring Thunderbolt or DSC).
 
People DO NOT buy 27" and 32" 4k displays to use them a "full 4k" (pixel-for-pixel) with Macs.
(perhaps a few do, but a VERY few)

People DO buy 27" and 32" 4k displays to use them in "HiDPI" mode, yielding working resolutions of either 1080p or 1440p.

When you connect the 4k display to the Mac (using the proper cable), the displays preference pane should offer you the options of 1080p (looks like 1920x1080) or 1440p (looks like 2560x1440).
 
People DO buy 27" and 32" 4k displays to use them in "HiDPI" mode, yielding working resolutions of either 1080p or 1440p.
Most people buy 27" and 32" 4K displays to yield working resolutions of either 2560×1440 or 3008×1692.

;)
 
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QHD or 2K is 2560x1440. That's less pixels than 4K. 4K is better and is much less expensive than 5K or 6K. You only want QHD for gaming with higher refresh rates.

You're not downscaling to 2560x1440 on the 4K display (or not upscaling 2560x1440 to 4K). You're downscaling from 5K to 4K. There's a difference. The Mac's Retina or HiDPI or "Looks like" modes draw objects and text twice as high and twice as tall as they would be on a QHD screen - everything has 4 times as many pixels so they are smoother and have more detail.

I like 4K just fine. None of those pesky 5K/6K connection issues (requiring Thunderbolt or DSC).
Thanks for the reply. If I get a 4K resolution and use looks like down to 1440p, does that not hinder performance and image quality? I'm just curious. Whereas a 2k monitor would be displaying at 2k with no looks like use? I am sorry I am not clued up on displays...
 
People DO NOT buy 27" and 32" 4k displays to use them a "full 4k" (pixel-for-pixel) with Macs.
(perhaps a few do, but a VERY few)

People DO buy 27" and 32" 4k displays to use them in "HiDPI" mode, yielding working resolutions of either 1080p or 1440p.

When you connect the 4k display to the Mac (using the proper cable), the displays preference pane should offer you the options of 1080p (looks like 1920x1080) or 1440p (looks like 2560x1440).
How do I know if my s2817Q has HiDPI mode?
 
Thanks for the reply. If I get a 4K resolution and use looks like down to 1440p, does that not hinder performance and image quality? I'm just curious. Whereas a 2k monitor would be displaying at 2k with no looks like use? I am sorry I am not clued up on displays...
There might be a performance drop but no one has done benchmarks because the drop is not noticeable or the drop in visual quality is not worth the performance increase. If you're gaming then you might want to choose the display's native resolution for best quality/performance or a lower resolution (not HiDPI mode) for better performance. For a 4K display, a game should performance the same using "Looks like 1920x1080" or 3840x2160 native.

How do I know if my s2817Q has HiDPI mode?
HiDPI modes are chosen by macOS, not the display. For a 4K display, the default modes will be HiDPI. You can get non-HiDPI modes by holding the option key and clicking "Scaled" in the Displays preferences panel, then selecting "Show low resolution modes".

SwitchResX can also show all the HiDPI and non-HiDPI modes in a list.
 
There might be a performance drop but no one has done benchmarks because the drop is not noticeable or the drop in visual quality is not worth the performance increase. If you're gaming then you might want to choose the display's native resolution for best quality/performance or a lower resolution (not HiDPI mode) for better performance. For a 4K display, a game should performance the same using "Looks like 1920x1080" or 3840x2160 native.


HiDPI modes are chosen by macOS, not the display. For a 4K display, the default modes will be HiDPI. You can get non-HiDPI modes by holding the option key and clicking "Scaled" in the Displays preferences panel, then selecting "Show low resolution modes".

SwitchResX can also show all the HiDPI and non-HiDPI modes in a list.
I won't be gaming, just some programming, general surfing and watching youtube here and. there but a lot of photoshop.

So is it better to get a 4k display and then select 2560x1440 mode or get a 2k display and work off 2560x1440 native?

Sorry to be a pain
 
I have the 21.5" LG Ultrafine. I use default display. This is the USB-C, not Thunderbold model, and the USB-C ports are USB 2.0. Which only makes them good for charging things, or really slow transfer speeds. Had I known that beforehand, I probably wouldn't got it.
 
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Thanks for the reply. If I get a 4K resolution and use looks like down to 1440p, does that not hinder performance and image quality? I'm just curious. Whereas a 2k monitor would be displaying at 2k with no looks like use? I am sorry I am not clued up on displays...
I went from a 1440p 27" monitor to 4K 27" as a second screen for my 27" 5K iMac. Using looks like 1440p on the 4K monitor is much better. It is not the integer scaling as it is on the 5K (5K means 2x2 pixels converted to 1), but scaling from a higher resolution is better than exact on a lower resolution. There is a performance hit, but it seems minor to me.
 
I have the 21.5" LG Ultrafine. I use default display. This is the USB-C, not Thunderbold model, and the USB-C ports are USB 2.0.
Back when that was current, USB-C didn’t allow for 4K at 60 Hz and USB 3.0.
 
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There might be a performance drop but no one has done benchmarks because the drop is not noticeable
There's definitely a performance drop associated with scaling on less powerful GPUs. When I hook up a “4K” display scaled to 3008×1692 HiDPI to my 2015 12” MacBook with its ultra-ultra-low-power Broadwell SoC, animations get very choppy.
 
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I was a little worried when I decided to go 4K. Thought the fonts might be so small for me in native resolution. But that wasn't a concern, as it turned out to be a awesome experience for me.
Went from 27" QHD to 32" 4K. Best Buy this year.
 
People DO NOT buy 27" and 32" 4k displays to use them a "full 4k" (pixel-for-pixel) with Macs.
(perhaps a few do, but a VERY few)

People DO buy 27" and 32" 4k displays to use them in "HiDPI" mode, yielding working resolutions of either 1080p or 1440p.

When you connect the 4k display to the Mac (using the proper cable), the displays preference pane should offer you the options of 1080p (looks like 1920x1080) or 1440p (looks like 2560x1440).
Do you have any references that back your claims? Many of us use 4K exactly because we need the screen estate.

Perhaps a majority uses "retina" scaling, but that's only because Apple deliberately makes it difficult to use native 4K, in order to sell Apple taxed displays. If there were sensible options to scale the UI, there would be no point in using "retina" scaling, because 4K native is as smooth as it gets on 32" and lower monitors.
 
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How do folks using a 27" 4k display "at full resolution" (pixel-for-pixel) read the menus?
Do they use a magnifying glass ?? :cool:
 
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How do folks using a 27" 4k display "at full resolution" (pixel-for-pixel) read the menus?
Do they use a magnifying glass ?? :cool:
System Preferences / Accessibility / Display / Menu bar size

Unfortunately, such preferences are not available for everything else.
 
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How do folks using a 27" 4k display "at full resolution" (pixel-for-pixel) read the menus?
I can read them just fine. I wear glasses to correct near-sightedness, resulting in pretty much perfect vision.

You seem to think that everyone wants text to be as big as on a 32” 1440p screen. Maybe you do. I don’t. :)
 
What happens when you go to System Preferences > Display and choose 'Scaled', then opt for one of the four available choices (from 'Larger Text' to 'More Space'?
 
What happens when you go to System Preferences > Display and choose 'Scaled', then opt for one of the four available choices (from 'Larger Text' to 'More Space'?
macOS draws a framebuffer four times the size of the specified "Looks like" resolution. If you select "Looks like 2560×1440", the resulting framebuffer is 5120×2880 pixels. The UI, text etc. is then drawn using HiDPI assets which are twice as wide and twice as high as the regular assets. Eventually, the framebuffer is scaled down to your display's actual resolution (e.g. 3840×2160). All that changes when going through these scaled options is the size of the framebuffer.
 
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