4th monitor not detected by R9 290

hughtrimble · 19 Feb 2016 at 22:45

Evening all,

I've been running three monitors (BenQ XL2411T flanked by two FlexScan S1921) off my Gigabyte Radeon R9 290 OC WindForce for a couple of years now, and now need to add a fourth.

The BenQ and two Flexscans are connected by DVI, DVI and DP-to-DVi respectively. The fourth monitor (Dell 1909W) is connected HDMI-to-DVI and shows up in the Control Panel's Devices and Printers section, but does not show in the Display Settings, and thus cannot show/duplicate my desktop.

All drivers are up to date as far as I can tell.

Any issues you can foresee driving four monitors off this one card and any reasons why it's detected, just not displaying anything?

Hugh

DrBombcrater · 20 Feb 2016 at 00:34

On the 290 only two DVI or HDMI ports in total can be active at once (this goes up to three if and only if all the connected monitors are identical). The third and fourth monitors need to be connected via a DP port, either directly or through an active converter.

Your three-monitor setup worked because DVI/DVI/DP is a valid combination for the 290, but DVI/DVI/DP/HDMI is not so the fourth one won't enable.

Often the best way to add a fourth monitor if you're not going to use it for games is to attach it to the motherboard graphics, or throw in a cheap card like a 5450 to run it.

Akagi · 20 Feb 2016 at 00:40

How utterly stupid.

hughtrimble · 20 Feb 2016 at 00:46

DrBombcrater said:
On the 290 only two DVI or HDMI ports in total can be active at once (this goes up to three if and only if all the connected monitors are identical). The third and fourth monitors need to be connected via a DP port, either directly or through an active converter.

Your three-monitor setup worked because DVI/DVI/DP is a valid combination for the 290, but DVI/DVI/DP/HDMI is not so the fourth one won't enable.

Often the best way to add a fourth monitor if you're not going to use it for games is to attach it to the motherboard graphics, or throw in a cheap card like a 5450 to run it.

Thanks for this DrBombcrater.

I didn't think you could have both a GPU and mobo outputting to displays at the same time? I thought it was either one or the other - just tried connecting the 4th to the mobo, and no output there. Any suggestions?

DrBombcrater · 20 Feb 2016 at 17:52

The on-board graphics hardware is automatically disabled when you plug in a graphics card so you'll need to change a setting in the BIOS to turn it back on. On my MSI Z97 board the setting is called 'IGD Multi-Monitor', but every manufacturer has their own name for it.

hughtrimble · 6 Mar 2016 at 15:42

DrBombcrater said:
The on-board graphics hardware is automatically disabled when you plug in a graphics card so you'll need to change a setting in the BIOS to turn it back on. On my MSI Z97 board the setting is called 'IGD Multi-Monitor', but every manufacturer has their own name for it.

Finally just got around to doing this, and interestingly the onboard graphics was 'enabled' in the BIOS all along...but no output detected from the HDMI port on the mobo. So I played with another setting (I can't recall what it was called...startup graphics or something?) and changed it from PCI 1 (something like that) to the onboard option.

After a strange first boot where none of the other screens worked, the second time, all works perfectly, with the fourth monitor now mirroring the third.

Exactly what I was after!

Thank you all, as always, for your help.