Hi guys, so I would like to know if connecting a 2015 15" MBP with the Iris Graphics that it comes with, would pair up with the U2515H at 60hz? I asked an apple rep on the phone and he said only the 2015 MBP with Radeon Graphics card upgrade would support 60hz but the Iris Graphics would not and probably do 40-50hz. He gave me this page as a reference https://support.apple.com/kb/SP719?viewlocale=en_US&locale=en_US but that talks about HDMI not mDP to DP. Also the U2515H monitor from Dell is a 1440p monitor. I've been hearing that you can connect the 2015 MBP with the Iris Graphics to a 4k monitor and get 60hz via the display port to a mini display port. So how is it possible an 1440P monitor would give less than 60hz when paired with the 2015 MBP?