Problem setting up 3 displays.

[pete820]

I recently got 3 monitors (LG 27MP33HQ-B) and I've been trying to get all 3 up and running but have been encountering a lot of issues getting the 3rd to work.

I have an HIS Radeon HD 7850 4gb iPower Turbo which has:
1x HDMI
2x DVI (one dual)
2x Mini DisplayPort

I bought 2 HDMI to Mini D-port cables, but now I'm reading that those may be "passive" adapters and not "active" and that's why my 3rd monitor won't display? I've never dealt with D-port before.

I've tried HDMI/DVI/MDP and HDMI/MDP/MDP and it doesn't seem to work. Do I need to get a so-called "active" adapter to fix this? would be annoying if I do, but it is what it is.

any help is appreciated.

 

[alexoiu]

Yes, for Eyefinity you need an active adapter display port to HDMI.

 

[JackNaylorPE]

This is a common complaint with AMD cards.....and with 144 Hz it's reportedly impossible. If I'm building for someone, I'll ask that they go nVidia.... no adapters req'd. Here's the 60 Hz soluition.

See last post here:

http://forums.amd.com/game/messageview.cfm?catid=474&threadid=172226

I recently purchased a Displayport hub from EVGA and while the advertising of aforementioned product is less than truthful, it did solve my problems. I wasnt able to connect all 3 VG248QE's to it as there simply isnt enough bandwidth in displayport 1.2 to fully support 3 VG248QE's. However, I was able to connect 2 of them and then with a second display port connect the 3rd and with the 14.2 beta drivers all 3 monitors have been working flawlessly for atleast 2-3 weeks now with no problems. However, I'm currently running 2x HD 7970's made by diamond.

I have been considering upgrading to R9 290x's however with only 1 display port on them I refuse to upgrade despite the fact that im drooling over the performance increase ive calculated based on higher bandwidth more pixel shaders, etc...

I have also had luck before acquiring my displayport hub with 2 active adapters made by Startech that were 99$ each and using 1 DVI-D and 2 active adapters with 3 IDENTICAL DVI-D cables. In order to avoid frustration in your efforts please make sure as much of your hardware is identical. My older setup I had the center monitor on DVI-D and the left and right on displayport active adapters and the center monitor had massive screen tearing horizontally whenever i panned right or left or moved a window across the center monitor, with 0 screen tearing on the left and right montior.

Also it is important to note that a few drivers back AMD changed the way crossfire functioned, my father used to use 2 dvi-d ports on his HD6970's and 1 display port with active adapters, upon updating to a newer driver release he was never able to get his crossfire + eyefinity to have all 3 monitors functioning together. Recently I went over to his house and swapped him from 2 dvi-d's and 1 displayport active adapter to 1 dvi-d and 2 displayport to dvi-d active adapters and it fixed all of his issues. I am not familiar with the R9 290x's as i do not own them however on older 6000 and 7000 series cards you can only use 1 legacy (vga, dvi, etc) adapter and 2 non-legacy (display port, etc) adapters in order for eyefinity to function properly.

One final note, It takes roughly 46% of the alloted bandwidth of a displayport 1.2 in order to run 1 vg248qe monitor at 1920x1080p@144hz which is roughly 12.5 gbps out of a totall 28.7 gbps that the displayport 1.2 is capable of outputting so you can run all 3 monitors using evga displayport hub but you will be stuck in 60hz unless you only connect two of them. this can be verified in the new 14.2 drivers as they have a meter on them when you are connected using MST technology that tells you the current usage of bandwidth per monitor using your Displayport.