Widescreen Gaming Forum

Looks like this new card takes a step backwards when it comes to handling more than three displays. There's two DL-DVIs, DisplayPort with MST support, and HDMI.

I haven't seen which version of HDMI it supports but I doubt there are any monitors that would accept, say, 2560x1600 using HDMI 2.0.

Those of us who use 1440p or higher resolution displays seem to be counting on luck on whether a MST hub supports three high resolution displays or not. I haven't gotten my Club3D hub to work with three 1440p monitors simultaneously, but it could also be due to my monitors / graphics cards / drivers...

2560x1600 @60hz 24bit Video bitrate = 5.9Gbit/s
HDMI v1.3/1.4 = 8.16 Gbit/s (340 MHz)

HDMI 1.4 should work!

3x 2560x1600 @60hz 24bit Video bitrate = 17.69Gbit/s
DisplayPort v1.2 = 17.28 Gbit/s (720 MHz)

Jep. That does not work!

So you can connect a maximum of 5 Monitory (all in 2560x1600@60hz) to the 290X IF you have a Monitor with Daisychain or a MST hub. Else it's 4.

Seems like 2560x1440 Should work with 6 Monitors as 3 Monitors only need 15.93Gbit/s
which should be covered by DP1.2 or is the overhead so big ? (edit: Nope! Overhead is excluded in this 17.28Gbit/s ! So i wonder why your MST hub did not work.)

But maybe in the Future there will be a Eyefinity 6 290X so you could connect 6 Monitors in 4k !

_________________
We gonna send it to outa space!

Of course, even if it does work you'll still get tearing if you mix DVI/HDMI (same thing, video wise) & DisplayPort.

Plus for my case, reportedly the Dell U2713HM is overclockable to 75Hz which would rule out 3 devices on a single MST hub.

As for 3 or more (m)DP ports, we'll have to see what the custom 290x cards bring concerning connection options. As far as rumors go, those should be out by the end of November. So here I'm hoping for a 5(m)DP card which will fit watercooling blocks.

Just to add to this, I gave it a try on my Sapphire HD 7950, using an MST Club3D hub. By default it allocates bandwidth for 75Hz even though you can't officially use 75Hz on a resolution over 1280x1024. Because of this, 2x 1440p screens use up 70% of the bandwidth of a single DP port and of course using 105% for 3 screens is impossible.

So without modifications you can't run 3x Dell U2713HM at 1440p on a single DP port. You may have better luck with a different monitor or perhaps you could convince CCC that they will only run at 60Hz. I actually plan on attempting to overclock them to 75Hz (at their native res, then in 5x1P eyefinity) so those suggestions are moot for me.

"Displayport Diagnostics" in the CCC ?

Never seen that. That's a new CCC or because of the MST hub ?

_________________
We gonna send it to outa space!

Just the regular September 2013 drivers. I'm sure it's because of the MST hub. In the port selection box, I can only select Port 1 (mDP, with the MST hub) and not Port 2 (mDP, single monitor). Which mostly makes sense. Until 4k 120Hz, I don't believe there's a single screen that can fill DP 1.2 bandwidth.


I forgot to add that a third monitor on the MST hub is detected but you simply can't use it. No output, unable for desktop arrangement and eyefinity.

Sorry for a late reply but now that I got a R9 290X I thought I'd give this a try.

I got all three 1440p working at the same time by reducing color depth(My Digital Flat-Panels - Properties) from 10 to 6.

Two panels at six bits per color would be enough, the third would have enough bandwidth left for 10 bpc.



It's not showing the information correctly though, all three are at 2560x1440, 60 Hz.

But did you use display port with an active adapter? I can't even get three screens working in full HD 60Hz with my reference 290. I am using 2x DVI and 1x HDMI. The third screen is recognized by Win7, but stays black and I can't add it to the desktop. I can add it to Eyefinity but then it still stays black...

Apparently when AMD said "you can use up to three cards without an active adapter" they really meant: you still have to use display port for one of the screens! you just don't need the active adapter anymore. So 2x DVI + 1x HDMI will not work, you have to use 1x DVI, 1x HDMI and 1x DisplayPort on the 290 reference cards that come with 2x DVI, 1x HDMI, 1x DP.
And because they also went from MiniDP to ordinary DP it means I have to buy a new cable or an adapter from DP to MiniDP.
Thanks, AMD!