5K 27" iMac vs. 27" 4K Monitor

[blairh]

Hello.

I'm debating between a 27" 5K base model 2017 iMac or a 27" 4K monitor (still debating which models).

I recently purchased a 2017 base model 13" rMBP. I would be using this rMBP with the 4K monitor attached via USB-C in clamshell mode plus a BT keyboard and mouse. I do have my concerns if this setup would be a smooth one where I can consistently wake my closed rMBP by pressing a key on my keyboard. I'm not entirely sure how I'd get my ethernet connection involved in this setup. (I don't want to buy dock.) Plus I'll need to connect some USB-A devices and my computer speakers.

My concern with the 27" 5k iMac is the glossy screen. My home office has a series of windows behind the screen which often times will reflect natural light. It's essentially a home office/green room with many plants behind me. It's truly the only place in my home for a desktop computer. Right now I'm using a 20" ACD which is matte.

I'm also curious how sharp text can be with a 27" 4K monitor/rMBP vs. a 5k 27" iMac. A rather popular Amazon review makes the case that a 27" 4K monitor on a Mac is not nearly as sharp or 'retina' as the 5K iMac. If you agree/disagree, I'd love to know.

Cost is also a factor. I can get a new 4K iMac for $1600 versus say a 4K 27" monitor for roughly $600 plus potentially a USB hub if necessary.

Thanks in advance for your answers.

 

[casperes1996]

My concern with the 27" 5k iMac is the glossy screen. My home office has a series of windows behind the screen which often times will reflect natural light. It's essentially a home office/green room with many plants behind me. It's truly the only place in my home for a desktop computer. Right now I'm using a 20" ACD which is matte.

I have a 2014 5K iMac. I also have a window roughly a meter away from it with natural light coming through from morning till early evening. I don't really notice it. Can you see it? Yes. But the anti-glare coating ont he display really works quite well. Though I do think it has faded a little over time (thus I point out it's from 2014), but still does a good job. There's a very particular spot near the camera, where it seems more faded than the rest though, so more glare right there. Otherwise I don't really notice it if I'm honest. Day to day it's great!

I'm also curious how sharp text can be with a 27" 4K monitor/rMBP vs. a 5k 27" iMac. A rather popular Amazon review makes the case that a 27" 4K monitor on a Mac is not nearly as sharp or 'retina' as the 5K iMac. If you agree/disagree, I'd love to know.

It's quite simple. If you want the Retine 2x scale, you cut your effective screen resolution in half. Thus a 4k screen is equivalent to a 1080p display in terms of usable area, if you want the same sharpness as a 5K in 2560x1440.

 

[blairh]

It's quite simple. If you want the Retine 2x scale, you cut your effective screen resolution in half. Thus a 4k screen is equivalent to a 1080p display in terms of usable area, if you want the same sharpness as a 5K in 2560x1440.

So the 4K text will be just as sharp as the 5K text, but with less usable area?

 

[casperes1996]

So the 4K text will be just as sharp as the 5K text, but with less usable area?

If you run it like that, yes. You can also choose to run the 4K at 2560x1440*1.5 instead, in which case you'll have the same space on screen as the 5K at 2560x1440x2, but with less sharp text.
And I mean, of course there are other differences in display technology that can impact perceived sharpness, but per the resolution, yes.

 

[MrX8503]

The 5K will have 2X scaling. The 4K will have 1.5x scaling. Both will have the exact workable space. To me, 5K is noticeably sharper, but that really depends on your eyes.

 

[casperes1996]

The 5K will have 2X scaling. The 4K will have 1.5x scaling. Both will have the exact workable space. To me, 5K is noticeably sharper, but that really depends on your eyes.

Oh really? Since the non-retina 21.5" iMacs are 1920x1080, I figured the 4K ones would use 2x scaling as well, for an effective work area of roughly 1920x1080 (little larger, since it's DCI-4k and not Ultra HD)

 

[MrX8503]

Oh really? Since the non-retina 21.5" iMacs are 1920x1080, I figured the 4K ones would use 2x scaling as well, for an effective work area of roughly 1920x1080 (little larger, since it's DCI-4k and not Ultra HD)

A 21” 4K will have 2X. A 27” 4K will have 1.5X scaling

 

[casperes1996]

A 21” 4K will have 2X. A 27” 4K will have 1.5X scaling

Oh that's how you meant it. Surely that depends on whether or not the display sends EDID/DisplayID information about it's size. Otherwise macOS has no chance of knowing how big the display is. But regardless, it's configurable via the scaling settings in System preferences.

 

[LiE_]

By default a 4K monitor will default to retina x2. So 1080p eqivelant. 1080p on a 27” is too low resolution and everything looks big/zoomed in. If you go 4K either get a 21-24” or make peace with the fact you’ll have to scale on the 27” to get 1440p but loose sharpness.

Personally for me I didn’t get on with 1.5x scaling on 4K 27”. Next to my MBP it didn’t look nearly as good. So I’d only go retina 2x scaling now.

 

[Fishrrman]

"1080p on a 27” is too low resolution and everything looks big/zoomed in. If you go 4K either get a 21-24” or make peace with the fact you’ll have to scale on the 27” to get 1440p but loose sharpness."

Once again, I'll point this out:
For someone who is older, or has less-than-excellent vision, 1080p on a 27" display can look just fine.

That's what I use and at nearly 70 with vision that ain't so good any more, I PREFER it.

The OP (if that's his pic in his avatar) is young and cannot understand this yet.
Wait 45 more years...!