Sign in with
Sign up | Sign in

Reply to this thread

Forum question

Started by wotwotwotwot | | 2 answers
How to run 3 screens off R9 280x?
I've got 3 screens that all work on my computer but only two at a time. One must always be disabled for the other two to work. What can i do to fix this? I have two 1080p monitors and one 1080p TV that i'm trying to connect. I have the two monitors in the dvi ports and the TV in the hdmi port. I've seen this graphics card pull off 3 screens so can anyone help me out in understanding how i get it to work with 3 screens? Thanks.
  • By posting on this site, I confirm I am over 13 years of age and agree to abide by the site’s rules.

September 17, 2014 3:12:13 AM

here is your reason i found from anandtech:

Quote:

Thanks to some firmware and board level changes, with the 200 series AMD is now able to attach multiple TMDS transmitters/interfaces to the same clock generator, allowing one clock generator to be used to drive multiple displays. As a result it’s now possible to drive up to 3 TMDS interface displays off of a single 200 series card, albeit with restrictions.

The catch here is that these can’t be independent displays, and this change is primarily intended towards enabling Eyefinity with cheap, DVI/HDMI-only monitors. To utilize clock sharing and to drive 3 such monitors off of a single card, all 3 monitors must be timing-identical, which functionally speaking almost always requires the monitors to be completely identical. Furthermore the sharing of the clock generator can only be engaged/disabled upon boot, so the 3rd display cannot be hot-plugged and must be present at boot time. Consequently this is by no means as unrestricted and easy as having native support for 3 TMDS interface displays, but for Eyefinity it will get the job done.

Of course this restriction only applies to using 3 TMDS interface monitors off of a single card natively. Using the DisplayPort, either with a native monitor or through an active DP-to-DVI/HDMI adapter, still allows the same fully independent functionality as before.


So short story, you system will only work with 3 monitor with eyefinity if all three monitor are identical. You HDTV will not work with this setup unless you buy another card.
September 17, 2014 2:52:27 AM

I think you might have to add a second 280x to do so. Even though most GPUs have say 4 ways to connect sometimes only 2 or 3 at a time are possible.

See all answers