Mac Display Resolution: ELI5

[kirbyrun]

Upgrading from a 5K 27" iMac (2015) to an M2 mini. And I have a question about display resolution.

I've always run my iMac with "Default" on for the display resolution. I foolishly assumed that this meant it was running at the full 5K. But when I checked recently, I realized that 5K makes everything teeny tiny, and that "default" is actually 1440p!

So, my question is this: If my 5K iMac is running at 1440p as a default, is there any reason to splash out for a new 5K display for my mini as opposed to a mere 1440p display? I could save a thousand bucks by getting a 1440p display since I’ll never run at the full 5K — the text is too damn tiny!

Or is there some benefit to running 5K-as-1440p that I'm unaware of?

 

[xraydoc]

Upgrading from a 5K 27" iMac (2015) to an M2 mini. And I have a question about display resolution.

I've always run my iMac with "Default" on for the display resolution. I foolishly assumed that this meant it was running at the full 5K. But when I checked recently, I realized that 5K makes everything teeny tiny, and that "default" is actually 1440p!

So, my question is this: If my 5K iMac is running at 1440p as a default, is there any reason to splash out for a new 5K display for my mini as opposed to a mere 1440p display? I could save a thousand bucks by getting a 1440p display since I’ll never run at the full 5K — the text is too damn tiny!

Or is there some benefit to running 5K-as-1440p that I'm unaware of?

Your iMac is using the full 5K resolution to make super smooth text that is sized the same as it would be on a 27" 2560x1440p monitor.
5K has exactly four times the number of pixels as a standard 1440p display, that's why text looks so good on a 5K display.

If you compared it to a standard 27" 1440p display side by side, you would immediately see the difference.

So, your iMac was using the full 5K the whole time. It's drawing text and UI elements at 200% of normal size so they're not microscopic. But since it's got more pixels to work with, curves and angles can look 4x as sharp as they would otherwise. Do this with only 2560x1440 pixels and edges will be jagged.

Think of 1080p video versus 4K video... the actors on the screen are the same size on both displays, but on one they're drawn with far more pixels so everything looks sharper.

Edit: Now, if you want, you can shrink the text size down a little to give yourself more desktop space. Text will still look good, but not quite as razor sharp as the exact 4x math with 5K going into 1440p. Or, as you discovered, you can set text to be basically 100% size at full pixel size. Text and UI elements are super tiny as you discovered.

 

[kirbyrun]

Your iMac is using the full 5K resolution to make super smooth text that is sized the same as it would be on a 27" 2560x1440p monitor.
5K has exactly four times the number of pixels as a standard 1440p display, that's why text looks so good on a 5K display.

If you compared it to a standard 27" 1440p display side by side, you would immediately see the difference.

So, your iMac was using the full 5K the whole time. It's drawing text and UI elements at 200% of normal size so they're not microscopic. But since it's got more pixels to work with, curves and angles can look 4x as sharp as they would otherwise. Do this with only 2560x1440 pixels and edges will be jagged.

Think of 1080p video versus 4K video... the actors on the screen are the same size on both displays, but on one they're drawn with far more pixels so everything looks sharper.

Edit: Now, if you want, you can shrink the text size down a little to give yourself more desktop space. Text will still look good, but not quite as razor sharp as the exact 4x math with 5K going into 1440p. Or, as you discovered, you can set text to be basically 100% size at full pixel size. Text and UI elements are super tiny as you discovered.

It's funny because right now I'm running a borrowed 4K monitor in 1440p mode, alongside Apple Cinema Display (with native 1440p) and I don't see much difference. But it's possible that's just down my aged eyes!

In any event, thanks for your discourse. It seems like you're saying that even though the number is the same (1440p), that the picture is still superior on a 5K display as opposed to native 1440p. You've given me a lot to think about.

 

[Amethyst1]

It seems like you're saying that even though the number is the same (1440p), that the picture is still superior on a 5K display as opposed to native 1440p.

As far as my eyes are concerned, there’s no comparison between the two.

 

[kirbyrun]

As far as my eyes are concerned, there’s no comparison between the two.

Your eyes are better than mine -- lucky!

 

[tstafford]

Your eyes are better than mine -- lucky!

Or maybe the opposite. If you can't tell the difference, the world of all monitors is open to you. If you can, you are stuck with about three very pricey choices.

 

[kirbyrun]

Or maybe the opposite. If you can't tell the difference, the world of all monitors is open to you. If you can, you are stuck with about three very pricey choices.

I like your perspective — makes me feel better about these aging orbs!

 

[Amethyst1]

I like your perspective — makes me feel better about these aging orbs!

The only thing that matters is that it works for you.

 

[xraydoc]

Or maybe the opposite. If you can't tell the difference, the world of all monitors is open to you. If you can, you are stuck with about three very pricey choices.

Yeah, this is true. My eyeballs are 53 years old but still good enough at monitor distance to see the difference. I guess I'm stuck with pricey displays for a while.

 

[kirbyrun]

Yeah, this is true. My eyeballs are 53 years old but still good enough at monitor distance to see the difference. I guess I'm stuck with pricey displays for a while.

Mine are a couple of years younger than yours, but I guess I got the bad OEM supplies at installation. 😅

 

[Basic75]

It's funny because right now I'm running a borrowed 4K monitor in 1440p mode, alongside Apple Cinema Display (with native 1440p) and I don't see much difference. But it's possible that's just down my aged eyes!

In any event, thanks for your discourse. It seems like you're saying that even though the number is the same (1440p), that the picture is still superior on a 5K display as opposed to native 1440p. You've given me a lot to think about.

Suppose you have three 27" monitors, a 2560x1440, a 3840x2160 and a 5120x2880. Here are the possibilities for everything at the normal "is or looks like 2560x1440" resolutions:

1. Mac renders in 2560x1440@1x and sends 2560x1440 pixels to the 2560x1440 monitor, this is the basic 1:1 pixel mapping case.
2. Mac renders in 2560x1440@1x and sends 2560x1440 pixels to the 3840x2160 monitor which scales it up to 3840x2160, this is probably the worst of all of these possibilities because you have a better monitor than 1. but get a worse picture due to non-integer upscaling.
3. Mac renders in 2560x1440@2x which is 5120x2880 pixels and sends a scaled-down to 3840x2160 pixel version to the 3840x2160 monitor, this is what many people do since a 3840x2160 monitor is much cheaper than a 5120x2880 and it's sharper than a 2560x1440, although some people including me don't like this because it's not pixel-perfect and the GPU has to do the extra downscaling.
4. Mac renders in 2560x1440@1x and sends 2560x1440 pixels to the 5120x2880 monitor, which is not something you would usually do because the result will look like 1. even though your monitor can do much better, either it's configured badly or you are trying to reduce the GPU load for gaming or so.
5. Mac renders in 2560x1440@2x and sends these 5120x2880 pixels to the 5120x2880 monitor, this is proper "retina" mode and looks the best, however it's expensive and there are not many options for these 200ppi monitors, not at this or any other size.

Whether you prefer 1. or 3 and whether you can see a difference between 1. and 3. and 5. depend on personal preference and eyesight, respectively.

 

[kirbyrun]

Suppose you have three 27" monitors, a 2560x1440, a 3840x2160 and a 5120x2880. Here are the possibilities for everything at the normal "is or looks like 2560x1440" resolutions:

1. Mac renders in 2560x1440@1x and sends 2560x1440 pixels to the 2560x1440 monitor, this is the basic 1:1 pixel mapping case.
2. Mac renders in 2560x1440@1x and sends 2560x1440 pixels to the 3840x2160 monitor which scales it up to 3840x2160, this is probably the worst of all of these possibilities because you have a better monitor than 1. but get a worse picture due to non-integer upscaling.
3. Mac renders in 2560x1440@2x which is 5120x2880 pixels and sends a scaled-down to 3840x2160 pixel version to the 3840x2160 monitor, this is what many people do since a 3840x2160 monitor is much cheaper than a 5120x2880 and it's sharper than a 2560x1440, although some people including me don't like this because it's not pixel-perfect and the GPU has to do the extra downscaling.
4. Mac renders in 2560x1440@1x and sends 2560x1440 pixels to the 5120x2880 monitor, which is not something you would usually do because the result will look like 1. even though your monitor can do much better, either it's configured badly or you are trying to reduce the GPU load for gaming or so.
5. Mac renders in 2560x1440@2x and sends these 5120x2880 pixels to the 5120x2880 monitor, this is proper "retina" mode and looks the best, however it's expensive and there are not many options for these 200ppi monitors, not at this or any other size.

Whether you prefer 1. or 3 and whether you can see a difference between 1. and 3. and 5. depend on personal preference and eyesight, respectively.

Thanks for this very comprehensive description!

I happen to have a 4K monitor, so just for the hell of it, I plugged it in alongside my 1440p monitor. Truthfully, I do see a difference...but it's not major and it doesn't really leap out at me. So I may just buy a cheap 1440p monitor to pair up with the one I already have so as not to tax my GPU too much with the scaling. If the upcoming Samsung 5K display is substantially cheaper than the Apple Studio Display, I may take the plunge.