5k iMac powerful enough for another 4k monitor?

cmm

macrumors 6502a
Original poster
Apr 30, 2006
769
11
NYC
Hi, I'd like to run another 4k monitor next to the 5k iMac. Will the imac keep up? Or will I deal with lagging/beach balls? I'm not doing any video or gaming, just need the screen real estate to code. Rather use the 5k iMac since I get an IPS 5k screen plus a computer, for the same cost of a Mac Pro, without the screens...

Would upgrading the GPU make any difference in my case?

Thanks!
 

cmm

macrumors 6502a
Original poster
Apr 30, 2006
769
11
NYC
It should work just fine on either GPU.
Why do you say that? One other person I've spoken to in #macosx said the opposite: He has 32gb ram, SSD and upgraded GPU and he notices a slight lag when he uses mission control. But he says it may be from Yosemite?

I just got off the phone with my business rep at the 5th Ave store and he said after conferring with colleagues, it is because people are using 30hz 4k monitors, not 60hz ones. And he insinuated that the $3500 Sharp one they have hooked up to the Mac Pro is best and won't have any lag.

I know I can return it, but it's such a pain in the ass and I want to get it right.

Advice sought. Thank you.
 

redheeler

macrumors 604
Oct 17, 2014
7,659
7,484
Why do you say that? One other person I've spoken to in #macosx said the opposite: He has 32gb ram, SSD and upgraded GPU and he notices a slight lag when he uses mission control. But he says it may be from Yosemite?

I just got off the phone with my business rep at the 5th Ave store and he said after conferring with colleagues, it is because people are using 30hz 4k monitors, not 60hz ones. And he insinuated that the $3500 Sharp one they have hooked up to the Mac Pro is best and won't have any lag.

I know I can return it, but it's such a pain in the ass and I want to get it right.

Advice sought. Thank you.
Mission Control lag is a known issue with Yosemite, especially on the M290X GPU.

As for the monitor you choose, any 4K that supports DisplayPort 1.2 should be fine. 60Hz is recommended for a much smoother experience.
 

cmm

macrumors 6502a
Original poster
Apr 30, 2006
769
11
NYC
Mission Control lag is a known issue with Yosemite, especially on the M290X GPU.

As for the monitor you choose, any 4K that supports DisplayPort 1.2 should be fine. 60Hz is recommended for a much smoother experience.
Does anyone know if Apple is going to fix it, or are they just going to ignore it?

On a Mac Pro, does that mean, I'd still have the lag from Mission Control?
 

ra004e

macrumors regular
Jun 8, 2009
143
21
I have base model now and used to have had upgraded M295X and mission control with a lot of windows open will be an issue. I think it's a transparency problem. I have since disabled it by using System Preferences > Accessibility > Increase contrast. With this setting I drive an additional Dell P2415Q 4k monitor with no lag what so ever on base unit.
 

cmm

macrumors 6502a
Original poster
Apr 30, 2006
769
11
NYC
I have base model now and used to have had upgraded M295X and mission control with a lot of windows open will be an issue. I think it's a transparency problem. I have since disabled it by using System Preferences > Accessibility > Increase contrast. With this setting I drive an additional Dell P2415Q 4k monitor with no lag what so ever on base unit.
Thanks! How bad does it look without the contrast increased? Can you screenshot?

So with the base GPU, no issues with a second 4k monitor, even when using mission control?

If this is a known issue, maybe apple will fix it with a bug fix release of Yosemite?
 

ra004e

macrumors regular
Jun 8, 2009
143
21
Thanks! How bad does it look without the contrast increased? Can you screenshot?

So with the base GPU, no issues with a second 4k monitor, even when using mission control?

If this is a known issue, maybe apple will fix it with a bug fix release of Yosemite?
Here's your screenshot

No issues with second 4k monitor even using mission control @ Best (Retina) settings. If you use higher scaled resolutions (i.e. looks like 3200x1800, etc ) it will have more work to do and will be less performant. Let me say that adding the additional monitor is not what makes Mission control lag. Mission control without Increased contrast setting turned on, is still fine until after 5 or more safari/browser windows are open, then lag starts to effect Mission control.

This is a known issue with apple support, I was told by their 2nd level support they were aware of the problem and it was a Yosemite issue and would eventually be fixed. They did not have an answer of when. So I continue to use my base unit with increased contrast turned on have and since forgotten about the whole issue as I've actually come to like the look better as the dark menu and dock is quite nice ( not pictured ).

Last thing you should look through forums for other 5k software issues. I know there are some adobe products mentioned. I use CC 2014 and have not noticed anything odd, but can only speak from my experience. Hope this helps.
 

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