So I went ahead and upgraded from Windows 7 to Windows 10. I've been running a triple monitor setup in Windows 7 just fine from 2, Crossfired, AMD branded Radeon 2GB HD7770s with DVI-I, HDMI & Displayports used for the monitors. In Windows 10 the max I can get is 2 monitors. When I first upgraded on reboot nothing was working, saw the boot screen, then blank. Pulled 1 card, no help so I just ran off the DVI and finally got into the PC on one monitor. I did the usual thing and deleted the drivers, loaded the latest Catalyst (15.7.1) drivers for Win10 and tried again. No difference. Borrowed a newer Radeon Sapphire R9 270x thinking it may be the card and it does the same thing. I am running 3 LG L2000CP monitors using the DVI input,. Here's what I get: with the following hooked up:.
1) DVI+HDMI+DisplayPort : Blank screens, 2 seem active, 1 not active
2) DVI+HDMI : 2 working screens
If I plug in the DisplayPort while booted, Catalyst will sometimes see a monitor when I detect monitors and if I try to extend monitor to it, it will switch on but my DVI screen will blank off.
3) DisplayPort + HDMI or DVI : 2 working monitors. same as above. no matter which 2 ports I used, 2 monitors work fine, if I plug in 3, DisplayPort monitor drops off
I'm going to try a different DisplayPort adapter but if you guys can think of something else to try also, it would be much appreciated.
Tried rolling back to Catalyst 14.9 drivers as suggested in other threads but it did not help.