I just bought a Sapphire RX 480 Nitro+OC 8Gb and there is something very strange with the DVI port.
Previously i was using a 7850 HD, with a random asus minotor. This monitor has no DVI port but two HDMI ports. I used to connect the DVI port of my 7850 to the HDMI port 1 of my monitor with a simple HDMI-DVI cable (DVI-D). When i first installed my new RX 480, i tried to connect it the same way, and it didn't work, there was no signal on my monitor. I unplugged/replugged the RX 480 and it worked. One day later, the signal was gone.
I tried to connect the HDMI port 1 of the monitor to the HDMI port of the RX 480 with a HDMI-HDMI cable : it worked.
Then i tried to connect the HDMI port 2 of the monitor to the DVI port of the RX 480 with the HDMI-DVI cable : it worked.
So in conclusion, i got this :
Case 1 : HDMI 1 monitor - DVI 7850 HD : works
Case 2 : HDMI 1 monitor - DVI RX 480 : doesn't work
Case 3 : HDMI 2 monitor - DVI RX 480 : works
Case 4 : HDMI 1 monitor - HDMI RX 480 : works
It doesn't make sense to me. The issue can't be associated with the monitor port 1 because it works in case 1 and 4, not with the GPU port because it works in case 3, not with the cable because it works in case 1 and 3.
So i can't figure where is the problem with the case 2. Can it be associated to drivers problem ?