Recently bought six Dell U2715H 27" 2560x1440 monitors (black Friday sales), and ordered an MSI R9 Fury X to upgrade from my XFX R9 290X so I could run all six monitors.
The monitors arrived before the Fury X, and I had three of them set up in 3x1 Eyefinity (portrait) using my 290X. Everything worked just fine.
Once I installed the Fury X, I ran into a very strange error when trying to set up Eyefinity while the monitors were in portrait orientation.
I have three of the monitors connected using the three displayports on the Fury X. If I put them in landscape orientation, I can use Eyefinity just fine. However, if I turn them so they are in portrait orientation, the Eyefinity tool treats the monitors as portrait during the entire calibration process (setting orientation, positions, and alignment) right up until it is finished. After the calibration is done (and my new eyefinity screen is "supposed" to appear), everything is all out of place, and the monitor displays are all messed up.
Images of what happens when calibration finishes:
The driver seems to be stuck between thinking that the monitors are in landscape vs portrait orientation.
With the screens so messed up, it was a huge chore just to maneuver the "Radeon settings" window into an area where I could see it so that I could disable Eyefnity and get a "normal" display back.
Intel i7 3930k 6-core 3.2GHz
MSI Big Bang Xpower II motherboard
(old video) XFX R9 290X (was using Crimson 15.11)
(new video) MSI R9 Fury X (Crimson 15.12)
OCZ RevoDrive3 PCI-e 240GB SSD (system drive)
Please post here if you find out how to resolve this. I am having the same issues with an ASUS R9 380, Windows 10, and 3x 1080p screens in portrait.
I'm hoping it will be resolved soon in a software update if nothing else.