Become a MacRumors Supporter for $25/year with no ads, private forums, and more!

12 Core + 64GB too slow to run two 4k Displays?

irock101

macrumors 6502
Original poster
Jul 26, 2011
279
25
Hey,

I have a MacPro with the following spec:

2.7Ghz 12-core with 30MB of L3 Cache
64GB DDR3 1866MHz
1TBI PCIe-based flash storage
Dual AMD FirePro D500 GPU's with 3G of GDDR VRAM each

My screen is a Dell UltraSharp 32" Ultra HD 4K. Yesterday I connected an additional DELL P2715Q 27" ULTRA HD 4K screen and the performance of my Mac slowed down drastically. I am using Bootcamp and OSX at the same time and Bootcamp was entirely out of order. Is the MacPro not capable of handling 2x4k screens or will another 32" work just fine? I am quite confused here and trying to trouble shoot the issue.

I want a dual monitor setup which is why I got the maxed out MacPro in the first place but its disappointing if I can't run them both at 4k. Even at scaled resolutions the performance was incredibly slow.
 

762999

Cancelled
Nov 9, 2012
891
509
hi, what type of connections did you use? it seems your display probably fell back to 30hz display mode. It happened to me on my PC. You could also check Activity monitor, this would tell you if your mac is busy (probably not). If your display are set to 30hz you will see very noticeable lag.
 

irock101

macrumors 6502
Original poster
Jul 26, 2011
279
25
Mini Display Port to Thunderbolt
[doublepost=1462788740][/doublepost]The main issue is I am using a parallels virtual machine running from the bootcamp portion that is slowing down tremendously.
 

762999

Cancelled
Nov 9, 2012
891
509
Mini Display Port to Thunderbolt

check if your displays are in 30hz! you will probably needs to do some test. Don't attach more than two displays to any bus

More information here : Mac pro display support link.


 
  • Like
Reactions: irock101

irock101

macrumors 6502
Original poster
Jul 26, 2011
279
25
Well obviously I can't daisy chain them like a Thunderbolt display.
 

762999

Cancelled
Nov 9, 2012
891
509
Well obviously I can't daisy chain them like a Thunderbolt display.

I think you confuse PORTs and BUSes. Are you using two separate buses? I really mean BUS not PORT.

BUS 0: port 1,3
BUS 1: port 2,4
BUS 2: port 5,6 & Hdmi 0

if you have one monitor plugged in port 1, the next one should be in port 2, not 3.

have a second look at the diagram I posted, displays should NOT be on ports sharing the same bus.
 
Last edited:
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.