RE: U3415W, Display Manager for OS X?
On the MacPro I only have available
3440x1440 2560x1080 2048x858 1600x670
all above formats are 21:9 , and the 1600x670 fits quite well with the PIP.
I have a different target, to use PBP at full screen , using 2 different ports from the Mac Pro . Doing this ( say connecting both MDP and the Hdmi) I can split the monitor in 2 squared displays, so I would need for each of them something like 1720x1440 or 1280x1080 , to maintain a proportion between x and y axis.
Dell wrote in this forum that this monitor is not optimised for Mac, so my only hope is Apple in the future to add in OS X drivers for the type of monitors to have a wider choice of scaling !