Only two screens can be active at the same time

I'm having the problem that only 2 monitors seem to work simultaneously. Right now I have these monitors:

Samsung SyncMaster S24B350 (VGA to DVI adapter)
Samsung SyncMaster P2450H (DVI to DVI)
Iiyama E2483HS (HDMI to DP cable)

and this setup:

Sapphire R9 270X
Windows 8.1
Latest drivers (according to AMD driver autodetect)

The Iiyama one is the one I'm trying to add to the setup. However it only works when I remove another screen.

When I look at my config this is the view I get (the not detected display is the onboard VGA adapter):

enter image description here

When I try to change it to 'extend desktop to this display', I get the "The display settings could not be saved. Please try a different combination of display settings." message.

In my search for an answer I have come across the statement that I need an active HDMI to DP adapter.

This is the cable I have:

enter image description here

Am I correct in assuming this is a passive one and that this is where the issue is located?

If not: what suggestions do you have to fix this?

Jeroen Vannevel

Posted 2014-02-20T15:09:53.450

Reputation: 238

Answers

To use more than 2 screens on an AMD card, at least one screen must use a (true) DisplayPort connection. Your cable is indeed a passive adapter (utilizing the HDMI fallback mode on DP+). As such, this is not a true DisplayPort connection.

Active adapters (or "converters") are usually advertised as such. Unfortunately, there are quite some low-quality products on the market that may not work. I suggest to go by Amazon ratings to improve your chances of finding a good one. This one looks decent enough.

Also, take note of the different plug sizes. Due to Apple's use of Mini-DisplayPort, these are the most common adapters.

Daniel B

Posted 2014-02-20T15:09:53.450

Reputation: 40 502

I have ordered an active adapter and will receive it monday, I'll get back to you to let you know how the situation is then. – Jeroen Vannevel – 2014-02-22T19:48:25.133

After I plugged in the HDMI cable together with the active HDMI-to-DP adapter I didn't get any vision and both my pre-existing screens restarted every 10 seconds. What could cause this? – Jeroen Vannevel – 2014-02-24T11:47:48.233

Which adapter did you buy? Feel free to link to your local store. – Daniel B – 2014-02-24T11:51:05.077

http://www.computerstore.be/product/330946/club-3d-displayport-naar-hdmi.html – Jeroen Vannevel – 2014-02-24T11:53:41.233

Unfortunately this adapter, expensive as it may be, appears to be passive. The DP++ logo also hints at this. The store does not have any active adapters on sale. – Daniel B – 2014-02-24T12:05:28.430

Geez. Alright, I guess I'll be sending that one back. Considering Amazon's one-month delivery times I'll accept (and award bounty) to your answer in a few days; I'll get back to this once I've received it. – Jeroen Vannevel – 2014-02-24T12:12:24.170

Received my active adapter a few minutes ago: plugged it in, detected all displays in the screen resolution config window, activated the new desktop and rearranged it a little. Works perfectly now. Thanks a lot for the constant followup help! – Jeroen Vannevel – 2014-03-07T13:37:02.113

Not sure if you have already seen this before, but an answer from justanswer might be useful for you:

When using mini DisplayPort-to-singlelink DVI adapters, quad output is divided into two pairs (displays 1 and 2, and displays 3 and 4). The displays used in each pair must be identical (with the same manufacturer and model number) and must be identically configured (with the same resolution)...

Source - Post by Shauqat about half way down the page.

Matthew Williams

Posted 2014-02-20T15:09:53.450

Reputation: 4 149

I'm using a (normal) DP to HDMI adapter so it's not entirely the same. I don't know for what types of adapters this applies though but I'll keep it in mind. – Jeroen Vannevel – 2014-02-20T15:26:34.627

Have you tried connecting one screen to the on-board graphics? Not the best option for gaming, but if performance isn't paramount, and your main goal is just having three monitors, it might be worth a try. There may be a setting change to be made in the BIOS to (re)enable the on-board graphics.

I've done such a thing on windows 7 and had 4 monitors running, 2 from an AMD HD6850, and 2 from the Intel integrated graphics.

As far as the active vs passive adapters, there's this page: http://support.amd.com/en-us/recommended/eyefinity-adapters

Smithy

Posted 2014-02-20T15:09:53.450

Reputation: 61