I have an HIS HD7850 which has two mini DisplayPort, one HDMI, and one DVI output. I am trying to connect it to three monitors - one Acer B273HU and two LG 1980U.
I purchased Sapphire and Accell active mini DisplayPort to DVI adapters and neither of them will produce an image on either the Acer or LG monitors, no matter the configuration or if the adapter is connected directly to DVI or adapted to HDMI.
I've tried the adapters on my HDTV on a different card (7870) and also on a spare BenQ monitor that has no stand which I use for testing. The adapters work on both the HDTV and BenQ monitor.
I have emailed LG, Accell, HIS, and AMD - LG said to lower the resolution (didn't work), Accell had no clue, and neither HIS not AMD have responded.
And here's the kicker - passsive mini DisplayPort to DVI and HDMI work on the Acer and LG monitors (of course then I can only get two monitors at a time to dislay so that's not an option).
Are there known issues between active DisplayPort adapters and certain monitors? Why on earth would the adapters work with certain monitors and not others? Can't figure this out for the life of me.