Does anyone use a 4k monitor as a second monitor for their iMac/iMac Pro?

[dapa0s]

I currently have a 1440p monitor as a second monitor for my home setup, and I'm wondering if I switch to a 4k monitor, how will that work? Will it be the same, or will switching windows from the iMac Pro's 5k screen to the 4k second monitor be more laggy?

 

[theluggage]

I currently have a 1440p monitor as a second monitor for my home setup, and I'm wondering if I switch to a 4k monitor, how will that work? Will it be the same, or will switching windows from the iMac Pro's 5k screen to the 4k second monitor be more laggy?

I have a 2017 iMac with Radeon Pro 580 and it happily runs a second 4k display even with non-integer "Looks like 2560x1440" to get the same physical text/icon size as the 5k screen. The result isn't quite as pin-sharp as the true 5k display (the "2560x1440" bit is misleading, since it is actually rendered at 5k internally with good-quality downsampling to 4k) but you probably won't notice the resolution difference, especially if you're using it as a secondary monitor off to the side of the 5k display. That's probably the sweet spot for a 27-28" display. You can also run it at raw 3840x2160 (tiny text - starts to get usable at 30"+ or 27-28" if you have the eyeballs of a 20 year old), "looks like 1920x1080" (rather big text and icons but pin sharp - suitable for 24" or smaller) or a couple of intermediate scaled modes.

Really haven't noticed any lag problem (maybe if you wanted to run complex 3D animations on both screens...?) and an iMac Pro should out-perform my regular iMac.

Only real dysfunction is that I've also got a 24" SD display connected and the combination can get a bit temperamental when waking from sleep or if you forget to turn both on. Probably not a problem with a single display.

 

[dapa0s]

Great, thanks for the info. I think I'll just go with a 4k 27 inch monitor, especially as I mostly just use it to watch videos, or as a second screen to the side to use for extra windows for logic.

 

[Fishrrman]

"I think I'll just go with a 4k 27 inch monitor, especially as I mostly just use it to watch videos, or as a second screen to the side to use for extra windows for logic."

For Logic, the 1440p display will give you more "working room" than 4k (which runs at "looks like 1080p" on the Mac).

An iMac with two external displays will need a lot of desk space!

 

[theluggage]

An iMac with two external displays will need a lot of desk space!

...but very useful for development (manual | code | app ) or logic (timeline | piano roll/score | plug-ins).

Not really relevant to the original question, but with hindsight I'd go for 24" displays as "side" screens - I've got a 24" (16:10, too) to one side and a 28" to the other and that puts the far end of the 28" in the next county. If only there were more 16:10 or, better, 4:3 screens around...

 

[roman.stapunov]

"I think I'll just go with a 4k 27 inch monitor, especially as I mostly just use it to watch videos, or as a second screen to the side to use for extra windows for logic."

For Logic, the 1440p display will give you more "working room" than 4k (which runs at "looks like 1080p" on the Mac).

An iMac with two external displays will need a lot of desk space!

4K can be run “looks like 1440p” and it will give the same working room as 1440p but will look dramatically better. I have both connected to Mac mini on my desc and 4K much better to work with

 

[dapa0s]

4K can be run “looks like 1440p” and it will give the same working room as 1440p but will look dramatically better. I have both connected to Mac mini on my desc and 4K much better to work with

Really? It looks even better than a native 1440p screen?