MacBook Pro (Retina, 13-inch, Early 2015) Dual External Monitor Performance According to the MacBook Pro (Retina, 13-inch, Early 2015) Technical Specifications, the Graphics and Video Support for the 2015 Retina MBP 13-inch is:


  
  Intel Iris Graphics 6100  
  Dual display and video mirroring: Simultaneously supports full native resolution on the built-in display and up to 3840 by 2160 pixels on up to two external displays, both at millions of colors.
  


There exist answered questions here on the Apple Stack Exchange about what's possible in terms of dual external monitors for this MBP. I understand that, as shown by the above quoted text, it is possible to run two 4K monitors with the MBP.

My question is concerned with the actual performance of using two full 2160p/4K external monitors with (at least) a Mini DisplayPort connection - has anyone had any problems (flickering, or really anything negative) with this setup? Similar to  this question, but for the 2015 MBP.

I guess the performance may vary with the brand of monitor, but I'm just looking for a general idea of how well it does. I'm interested in knowing about how it would function before I make the costly investment.

I know the Intel Iris Graphics 6100 are integrated and use up to 1.5GB RAM of the MBP, but I don't know if that will mean a stable, reliable experience with two 4K monitors. I also know the Retina 15-inch 2015 MacBook Pro uses a discrete graphics card, which may be more suitable, but I'm not interested in the 15-inch screen.
I had this exact same question, and found the answer on Apple's discussion forums:


  A final update - I got my hands on two Dell P2715Q's which support 3840x2160@60Hz over SST. I'm happy to report the new 13" RMBP happily drives both displays at their native resolutions with 60Hz refresh in single stream mode (the default).


https://discussions.apple.com/thread/6868583