3x R9 290s in eyefinity. Third monitor is detected by I can't enable it?

bpfergu

Distinguished
Jun 20, 2009
33
0
18,530
I am trying to set up 3 27" monitors for eyefinity but I can't seem to get the third monitor to show any picture. From what I understand the R9 290s no longer require the usage of a display adapter.
I have 2 monitors connected DVI>DVI into a GPU and I have the last monitor (that is not displaying anything) DVI>HDMI into the same GPU.
What am I doing wrong? Thanks!
 
Solution


hmm... yeah I too was under the impression that AMD rearranged the pixel clock and TMDS pairs such that DisplayPort was no longer needed for Eyefinity. Are you able to activate the third display if the second is disabled?

EDIT: HardOCP tested 2x DVI + 1x HDMI on the 290x and verified that it works

http://www.hardocp.com/article/2013/11/01/amd_radeon_r9_290x_crossfire_video_card_review/#.UseuyPRDtH8
 

bpfergu

Distinguished
Jun 20, 2009
33
0
18,530


The only way I can seem to show anything on the third display is if I unplug the DVI>DVI cable from one screen and put it into the third screen. Then the screen that I replaced with the DVI>HDMI doesn't show anything.

However, it still detects there being a screen in CCC. I just can't activate it or do anything with it.
 


Your wording is a little confusing. Test each port individually on its own using a display that you know works in order to verify that each port works and there are no electrical faults. Plug one display into the first DVI port, then the second DVI port, and then the HDMI port.
 

bpfergu

Distinguished
Jun 20, 2009
33
0
18,530


The two DVI cables work on all 3 monitors. The DVI>HDMI cable doesn't work on any monitor, even when it is the only cable plugged in. However, it still detects when I plug the HDMI cable in and recognizes that a monitor is plugged in, however I can't activate the monitor or do anything with it.
 


Do you have an HDMI device that you can test with an HDMI to HDMI cable? The only difference is the physical connector, but it would be nice to rule out the HDMI to DVI cable as the culprit. My suspicion is that it's a fault on the board and that the GPU will need to be replaced.
 

bpfergu

Distinguished
Jun 20, 2009
33
0
18,530


Unfortunately I do not have anything HDMI to HDMI to test. That being said, I don't think that has anything to do with the GPUs. I swapped out all 3 GPUs and none of them would display the monitor with the DVI>HDMI cable attached. However, all three would make the "connect noise" whenever the hdmi cable was attached and the "disconnect noise" whenever it was unattached. In addition, all three would show that a third monitor was connected, but I couldn't do anything with it.

It's almost as if, despite what everything is saying, I will still need a displayport adapter for this setup.

Edit: Alright, I messed with it some more. I found an older monitor (1920x1080) and when I hooked up the dvi>hdmi cable it displayed fine. Do dvi>hdmi monitors not work on 1440 displays?
 


The fact that the HDMI to DVI cable doesn't work on any of 3 displays known to work even when it's the only display attached, and that it doesn't work across 3 GPUs (I assume that you have 3x R9-290) makes it almost certain that it's a cable issue.
 
I just saw your edit, HDMI and Single-Link DVI do not provide enough bandwidth to drive anything above 1920x1200. 2560x1440 and 2560x1600 can only be driven by Dual-Link DVI-D or DisplayPort.

Are all three of your 27 inch displays identical? My understanding is that the 290 and 290x have each one Dual-Link DVI-D, one Single-Link DVI-D, one HDMI, and two mini DisplayPort.
 

bpfergu

Distinguished
Jun 20, 2009
33
0
18,530


Please see my edit. The cable worked fine on a non-1440 monitor. A quick google search is stating that there are issues with running hdmi on such high resolution monitors and that I might still have to resort to a displayport adapter thing. Does this sound plausible to you?
 

bpfergu

Distinguished
Jun 20, 2009
33
0
18,530


All 3 monitors are 27" QNIX 2560x1440 and only have a single DVI-D output.

The 290s have 2 dual-link DVIs, one HDMI, and one display port. So it sounds like I will need to hook up the third monitor via the display port.

Would this item suffice?

http://www.newegg.com/Product/Product.aspx?Item=N82E16814999030
 


Ah yes, 2x Dual-Link DVI-D makes sense. The Dual-Link DVI-D has enough bandwidth to drive the display, but the HDMI port does not. With that said though a 2560x1440 display should still work on a Single-Link connection, just at a lower resolution. My suspicion is that all of the TMDS pairs are being gobbled up by the two Dual-Link DVI ports when they're running in Dual-Link mode. I can't find any documentation to support this so it's just a hunch.

Do you by any chance have any Single-Link DVI-D cables lying around? Perhaps from an older display? If you do, try swapping one of the Dual-Link cables with that one and see if the third display pops up. This would indicate that the TMDS outputs can be configured as Single/NC/NC, Dual/NC/NC, Single/Single/NC, Dual/Single/NC, Single/Dual/NC, Dual/Dual/NC, Single/Single/Single, Dual/Single/Single, or Single/Dual/Single, with those being the link speeds on the DL-DVI-D-0, DL-DVI-D-1, and HDMI ports respectively. NC stands for No Connection. What you want to configure is Dual/Dual/Dual, but are limited by the number of TMDS pairs in the HDMI cable to Dual/Dual/Single but that doesn't seem to work. This would seem to indicate that there are at most 12 TMDS pairs available; Single-Link DVI-D and HDMI require 3, and Dual-Link requires 6. I'm going to dig around for some documentation but I would appreciate it if you could test this for me.

EDIT: That adapter is only DisplayPort to Single-Link DVI-D. Here's one that supports Dual-Link DVI-D output

http://www.monoprice.com/Product?c_id=104&cp_id=10428&cs_id=1042802&p_id=6904&seq=1&format=2
 

bpfergu

Distinguished
Jun 20, 2009
33
0
18,530


Sorry for the delay in responding. So I found what I assume is an older DVI cable (it only has 18 pins) and tried plugging it into one of the monitors. When I do so, the monitor just flickers like crazy in a weird purple color.

So as of right now:
Dual link DVI works perfectly on all 3 monitors.
HDMI detects the monitor but doesn't display anything
Old DVI cable makes the screens flicker a weird purple color
Does that mean that these monitors ONLY display in dual-dvi?

Does this mean that I will HAVE to get the adapter thing for this to work? Also, the one you linked was for a mini display port. Would I just need to find one of those except with a regular-sized display port?

Thanks for the help so far.

UPDATE: I went ahead and purchased:

http://www.newegg.com/Product/Product.aspx?Item=N82E16812400320

So hopefully this will take care of my issue. Will definitely make sure the next monitors I purchase have a displayport attached on them to go along with dual DVI.
 


Okay, it seems like the displays don't like Single-Link at all then.

As for the adapter, I wasn't aware that AMD went back to full sized DisplayPort, I thought that they had settled on mini DisplayPort. If yours has a full size DispayPort, get a converter for that
 
Solution