How´s MBPr 15" Late 2016 with 4k monitor attached?

[Fravin]

So, I´m wondering about it.

The Radeon Pro 450 inside MacBook Pro Retina 15 Late 2016 looks good in theory. But How is the machine performmance when plugged in an 4k monitor?

My 4k monitor is a Dell S2817q, with Displayports and HDMI.

It´s sanppy enough to use booth displays?

 

[shoehornhands]

So, I´m wondering about it.

The Radeon Pro 450 inside MacBook Pro Retina 15 Late 2016 looks good in theory. But How is the machine performmance when plugged in an 4k monitor?

My 4k monitor is a Dell S2817q, with Displayports and HDMI.

It´s sanppy enough to use booth displays?

The 2016 15" MacBook Pro has 2 video cards in it (the Intel graphics integrated into the processor, and the dedicated AMD chip). When you're just using the MacBook Pro's display, most of the time the dedicated AMD chip isn't even used (it's only activated if / when you do something graphically intensive). If you plug in an external display, the dedicated chip will be used to drive the external display, while the integrated Intel chip is used to drive the MacBook Pro's display. In other words, the dedicated AMD chip should have no trouble driving a 4k display, and running both the internal MacBook Pro display and an external 4k display will not cause any degradation in performance.

 

[Fravin]

Thank you!

 

[csurfr]

I'll echo the above statements. I have a 2017 15" and with its marginally better graphics card, I have absolutely zero issues driving my WQHD 34" UltraWide LG Display. Granted it's not 4k, but it's pretty close as far as pixels goes (3440x1440 I think). I noticed that the dedicated card was running, but prior to reading what @shoehornhands said above, I had no idea the machine switched because of the external display. No complaints at all.

 

[mj_]

If you plug in an external display, the dedicated chip will be used to drive the external display, while the integrated Intel chip is used to drive the MacBook Pro's display.

I don't think this is true. From my understanding all displays are always driven by the same video card, either internal or external. It's true that as soon as you plug in an external monitor, the system immediately switches over to the external GPU but it does so for both displays, internal and external. You can use a tiny tool called gfxCardStatus to check what GPU is currently in use and to switch between them if necessary.

That said I agree with the rest of the statement. I have a 2015 MBP with AMD R9 M370X GPU, which is significantly slower than the R455 or R460 on the newer models, and even that is more than powerful enough to drive an external 4K display without any noticeable lags. And I have both displays, external and internal, set to maximum a different scaling factor other than "Default", which means the GPU has to move MUCH more pixels around.