Eyefinity and active vs passive adapters.

Psykomantis00 · April 8, 2014

Hi everyone. So I figured out my previous gpu problem but I'm still having some weird issues. I have a Radeon 7990 that when I first installed it, I had 3x1 Eyefinity and I was trying to get a 4th display working but kept getting an error when saving the resolution. I decided I'd rather use my higher resolution monitor than the 3 way eyefinity so I disconnected 2 of the Samsung displays. Well this morning I decided I wanted my eyefinity back so I disconnected the 24in monitor and hooked all 3 samsung displays back up. Now I can only get two of them to work where I had 3 working previously through the same connections.

The only thing I can think of is that I need active adapters for anymore than 2 monitors. What bothers me is that they worked fine the way I have it connected now. I've done just about everything I can think of to try and fix this problem but nothings working. I've tried all different outputs on the 7990. I've tried different hdmi cables, displayport to hdmi adapters and even dvi to hdmi adapters. I deleted the samsung registry keys. I deleted the catalyst drivers and removed all AMD software with their removal tool (which I just found today, pretty nifty). I am pretty much grasping at straws here. I have an active displayport to hdmi adapter, but the 7990 only has mini dp or dvi. I ordered a mini dp to regular DP adapter so I can use my active DP adapter and I'll report back on thursday when that arrives.

Part of me is wanting to just format and start from scratch to see if the displays will work again, but I've done that so many times this week that I just am tired of re-installing skype and chrome and all that crap.

Can anyone confirm that I would need active adapters over mini dp passive adapters? Why would it work before and not now?

GamerDude · April 8, 2014

Yep, I believe you're gonna need an active mini-DP to HDMI/DVI adapter for it to work in EF mode. I had a 3 way HD7970 setup before going two way R9 290X, with the HD7970's I had to used an active mini-DP to DVI (I prefer DVI) adapter for the 3rd monitor to work. I'm not sure about the R9 280 series and below, but with the R9 290/290X, there's no need for an active mini-DP, I'm actually using two DVI and one HDMI ports for my monitors.