(AMD support referred me to you... see below)
A few months ago, I wanted to try Win10, so I updated all drivers, including graphics...
While still on Win7x64 EN pro with driver version Omega 14.12 everything was fine...and after upgrading (only the graphic driver) to 15.7.1, 2 displays were disabled (they are shown in the Catalyst Control Center, but nothing happened when I try to extend or duplicate to activate those displays).
I then reverted to 14.12 (still on Win 7) and those 2 displays were up and running again.
Then I updated to Win10 and was forced to use the newest graphic driver (since 14.12 doesn't support Win10).
The setup is:
Main card: Radeon R9 280X (Sapphire Vapor-X) with main display (LG W2442PA, 1080p)(working) connected via HDMI, 2 others displays connected via DVI (LG W2242TQ, 1680x1050 native and max)(not working)
Second card: Radeon HD5450 with 2 LG W2242TQ connected (one via DVI, the other via VGA) (both working fine, before and after the update)
or more friendly schematic (with numbering... useful further below):
#1 R9 280X (HDMI) --> (HDMI) LG W2442PA
#2 R9 280X (DVI) --> (DVI) LG W2242TQ (those 2 were the one not working)
#3 R9 280X (DVI) --> (DVI) LG W2242TQ (those 2 were the one not working)
#4 HD5450 (DVI) --> (DVI) LG W2242TQ
#5 HD5450 (VGA) --> (VGA) LG W2242TQ
Since then, I've contacted AMD support... and the final verdict... this is beyond their capacities to help me (they referred me to this forum)
If you want to see the setup and the behavior (The display that are not working in windows are working in the bios stage): https://www.dropbox.com/s/cgealoayrquh6r3/boot_to_catalyst.mp4?dl=0
(and all info provided to the support is avaliable here: https://www.dropbox.com/sh/u4pr4pvw3xgxkpx/AAAoLnbt03yUrh14D2BMPFC3a?dl=0)
What has been done and tested:
In the end... I (currently) can have 4 displays at the same time (and choose to have #1 #2 #4 #5)
Does anyone have any idea to help me out on this / help me understand why I worked fine before and now it doesn't?