Is there a way to connect 4 monitors to one computer?

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Astralv

Astralv

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May 6, 2013
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I posted more detailed question under the "displays" section of the forum and got no replies in 48 hours, so I wanted to rephrase my question. Original post with more info is here: http://www.tomshardware.com/forum/id-3094199/connect-monitors-motherboard-graphics-dedicated-amd-graphic-card.html

I can not get 4 monitors work with my AMD 7850 HD card. I connect 2 monitors to the grapgic card (HDMI and DVI-D) and one monitor to motherboard graphic via DVI-D. I want to connect 4th monitor, but the moment I connect it to the VGA on motherboard graphics, the monitor connected to the HDMI port on AMD turns off.

My AMD 7850 is 2013- it was the time when 3 monitors were not working with one graphic card because DVI and HDMI had the same signal and needed some kind of active amplification. Then there was Ifinity that was supposed to let us connect 3 monitors... I only connect 2 monitors to AMD and want to connect 2 more to the motherboard, but can only connect one.

Looks like it is some kind of Windows limitation. I want to duplicate signal on 3 monitors and extend desktop to 4th, or at least duplicate 2 and extend desktop on 2. I can accomplish 3 monitors in extended mode or 2 in duplicated and 3rd extended desktop. 4th would not get detected.

So- is it Windows limitation in recognizing 4th monitor, or graphic cards? Let's say I buy 2nd graphics care- would it give me more monitor ports? Would it let me connect 2 monitors to each graphic card and Windows will have no issue with it? Would I need exactly the same graphic card or should I buy any mid range graphic card under $200? Would it matter? Would I need a |crossfire"? I don't play games- this is music production workstation. I just need 4 monitors of which 3 in duplicate desktop mode. Any suggestions? I did consider the DVI splitters but I use 2K monitors and there are no splitters that support my monitor resolution. Thank you.
 
Solution
ThomasLeong
You wrote:
"...Is there a way to look up exact model of graphic card other than on the box? My box is too far under other boxes in the storage. My card has DVI-I and DVI-D, HDMI and full DP."

Google for 'ASUS HD7850"...and choose the ASUS site. There, type HD7850 in Search. There are 5 versions, and if yours has 2 DVI ports, looks like either the HD7850-DC2T-2GD5-V2 or the HD7850-DC2-2GD5-V2, or HD7850-DC-1GD5.

"The 2560x1080 monitors require dual link to run, also I think it looks the same with DVI-I and DVI-D, it just forces me to switch to DVI-D from I when HDMI connected."

Sorry I am not familiar with a dual-link DVI connection. Does this mean you have to use both DVI ports (DVI-D and DVI-I) to connect to one monitor, whilst the...
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first two monitors will work either with DVI, HDMI, VGA, or Displayport

any monitors past the first two MUST use Displayport.

either a DP connection or using an ACTIVE Displayport adapter
 
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Right now I have 2 monitors on AMD graphic card at HDMI and DVI-D, and one monitor at motherboard graphic card DVI-D port. My motherboard graphic only offers HDMI, DVI-D and VGA. My AMD graphic does have Display Port. So you recommend to connect 4th monitor to AMD graphic card? I have passive DP to VGA cable and I might have DP to HDMI cable somewhere- would be great if I could find it and test it...
 
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Ok, it works with DP to VGA cable! I am so excited to see all 4 monitors! Thank you so much. Also- it would not let me duplicate desktop on 3 monitors. I don't understand why it is so hard for Windows- just send the same signal on 3 ports. But the options only let me duplicate anything on 2 monitors. It would even duplicate 2 nondesktop views. I need desktop to be visible from 3 locations (I am a keyboardist and my synthesizers located at both sides of my desk, so I need to see the desktop while I recording because this is were my "Record, play and stop" buttons are.). In extended mode I would have to drag the entire DAW interface to another screen. Which is ok- at least the screen is working, so thank you again.
 
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If Windows won't allow mirroring to more than 1 other display, then use a 1-in, 2-out or 1-in, 3-out VGA or HDMI Splitter. What the box does is accept one input, and mirrors it to 2 or more outputs. Amazon should have one of those.
 
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Yeah, I had a VGA splitter. But I changed 2 of my monitors to 2K (2560 x 1080), and there is no DVI slitter supporting such resolution. Did not look in to DVI splitters, also the 3rd monitor that I wanted to be in duplicate mode is 1920 x 1080, so it would not work right... I will have to drag the user interface to that monitor in extended view, I guess. But thank you for the suggestion.
 
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DVI splitters are not cheap. A HDMI splitter is cheaper. You would need at least HDMI 1.3 I think for a greater than HD resolution. HDMI 1.4 is slightly more expensive but supports up to 4K/UHD (3840x2160).

So here is a possible solution:
1 HDMI splitter + 2 HDMI-DVI adapter plugs (assuming your 2560x1080 monitors can be connected via DVI).

Then connect the HDMI from AMD graphics card to one of your 2560x1080, and split with the HDMI Splitter to the other 2560x1080. In Windows, mirror the 2560x1080 to the 1920x1080 and you would then have 3 instances of your desktop. Your 4th monitor would be an extension of the desktop.
 
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Just when I thought, the issue is solved, it did not work the way I expected. The 4th monitor did work when connected with DP to VGA cable. But the cable is too short. I got DP to HDMI cable, 10 Ft. Connecting, and my main 2 monitors connected to DVI and HDMI in "duplicated desktop" mode get disconnected the moment I connect 4th monitor DP to HDMI. So how come DP to VGA works but DP to HDMI does not? The same DP is connected to computer, should not matter what is on another end.

I did not want to use HDMI splitter. There got to be a way.
 
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mmm...perhaps we should backtrack a bit to troublshoot.

Meanwhile, I re-installed my old ASUS HD6950 today, and I am able to get at least 4 displays without problem, including once using the HDMI output of my onboard gfx whilst the other 3 were from the HD6950 (DVI-I, HDMI, and one of 2 mDP-DVI). Since your HD7950 is a generation newer than mine, there should be no problem with 4 monitors.

1. Get into your BIOS, and confirm that it is enabled for iGPU or multi-monitor (however, it describes it). This allows your motherboard to work with BOTH a third party graphics card and the onboard graphics, rather than either or. Save and exit.

2. Look at the box of your HD7950. There should be a diagram on it that shows the connectors available. In that diagram, is the HDMI and DVI linked together such that when one is connected, the other is disconnected?...or any links between any two ports?

I have also an ASUS HD7970 which shows one of the two DVI-D ports linked with the HDMI (i.e. one or the other), but there is a small switch at the top of the card that unlinks them taking the DVI-D down from dual-link DVI-D to single-link DVI-D. Check yours.

3. Please detail again how your connections run, eg. HD7950 to DVI and HDMI mirrored, and onboard to HDMI and VGA. A diagram would help (if this forum does not allow diagrams, then dropbox so I can have a look).

4. I think your HD7950 has 2 miniDP, one HDMI and one DVI-D. You can use the 2 mDP to 2 of your monitors. But if I'm not wrong, anything more than 2 monitors would require an ACTIVE mDP-DVI (or ACTIVE mDP-HDMI or ACTIVE mDP-VGA) adapters. You can try with non-active adapters but again if the non-active works, it takes the lowest priority in the chain (ie. probably as Monitor 4).

5. What do the two 2560x1080 monitors have as inputs - DVI? DP? HDMI?

6. What do your other 2 monitors have as inputs - DVI? DP? HDMI? VGA?

7. Do any of your monitors have a loop through DP output?...because this would allow you to daisy-chain monitors as in DP out of graphics card - DP in at monitor 1 - DP out of monitor 1 - DP in of monitor 2.

8. Lastly, hope you know that when you hot unplug and hot plug monitor ports, Windows takes a few seconds to re-detect and re-configure. Hope this is not why you say the monitor disconnects?
 
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I had setting in BIOS enabling use of motherboard and dedicated cards, it should be enabled, otherwise, it would not let them work at the same time.

My graphic card is Asus Radeon 7850HD. 78, not 79. It would take a while to find the box- may be later tonight.

I have KVM switch that I did not mention that slightly complicates the situation. It is 2 computer ports, 2 monitors ports KVM switch. The KVM is working as expected, also it may confuse the Windows or send some weird signals- who knows. But if forget that KVM is there,

Monitor 1: 2560x1080 resolution, connected DVI-D to DVI-D port (to KVM switch, then to DVI-D) on 7850. "Duplicate desktop" Dual link.

Monitor 2: 2560x1080 resolution, connected HDMI to HDMI on 7850, no KVM between. "Duplicate Desktop"

Monitor 3- 1920x1080- connected to DVI-D on motherboard graphic card, through KVM switch- Extended mode.

Monitor 4: 1920x1080 seen working with DP to VGA on 7850 (extended mode), but not working with DP to HDMI on 7850. No KVM on that monitor.

No DP on motherboard graphic.
 
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Is this your card? -
https://www.asus.com/Graphics-Cards/HD7850DC22GD5/gallery/

If yes, the DVI port is DVI-I, not DVI-D (DVI-I has 4 extra connecting points around the single slit '|' )

Sorry, more questions -
Why do you say it is dual link in your description above, 'cos DVI-I is usually single link. If Dual-link DVI is true, it takes up more resources and this may be the limiting factor to use more monitors than what you think the card is capable of.

Let me digest the rest of your post above, and get back to you later.
 
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Manual for your motherboard P8Z77-V PRO says it has DP, HDMI, DVI-D, and VGA ports, of which you have used the DVI-D port for Monitor 3. The mobo should be able to drive at least 3 monitors.

For Monitor 4, instead of drawing from your graphics card, have you tried connecting from your motherboard? Try that DP-HDMI 10ft cable you bought. If it still does not work, try VGA-VGA, or male HDMI - male HDMI cable from mobo to female HDMI - male DVI Adapter to female DVI - male DVI cable to the monitor which, if it has it, should be a female DVI port. (Think I've got the male-female parts correct - no pun intended. Else note carefully before you buy).

Edit:
Had a re-look at your description of usage, and motherboard ports, please try HDMI-HDMI from motherboard to monitor 4. No adapters required.
The mobo HDMI 1.4a, according to mobo manual, is max 1920x1200 @60Hz so should be ok with your monitor 4.
 
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Ah...we have a slight misunderstanding here. Not that important except that the connector size is different. Signals are the same.
DP is full Display Port size
mDP is miniDisplay Port size, which is the top two ports from your graphics card.

So your 10ft 'DP-HDMI' cable must be mDP-HDMI else it would not have been connectable to the graphics card. Likewise your 'DP-VGA' which would be mDP-VGA. Hope that is correct.
 
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Additionally, I am not sure if you have LucidLogix Virtu MVP installed with your motherboard graphics. If you have, page 5-9 (topic 5.3.2) may be relevant to your use of the onboard graphics with a discrete graphics card - the i-mode or d-mode setting.

Personally, I would uninstall LucidLogix Virtu MVP in order not to complicate things. Seems more for games than for work.
 
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I have to read your suggestions and try more things. But this is not my graphic card. Is there a way to look up exact model of graphic card other than on the box? My box is too far under other boxes in the storage. My card has DVI-I and DVI-D, HDMI and full DP. The 2560x1080 monitors require dual link to run, also I think it looks the same with DVI-I and DVI-D, it just forces me to switch to DVI-D from I when HDMI connected.

The motherboard is Thunderbolt edition, it does not have mDP- not that I can see it. Also it would not work with 4th monitor. It does not matter where I connect it- feels like it Windows limitation. But I will test more.
 
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Clearer now.

Yes, I now see, on Para 2.3.11 pg 2-46 of your manual, that your mobo, the Thunderbolt version, does not have DP port, only VGA, HDMI or DVI, and Thunderbolt. According to the diagram, the HDMI and DVI ports seem to be linked, meaning only one can be used at any one time. Clues are the single line to the two different monitors, and the table on the same page listing only the HDMI under label 8.

Since you are already using the DVI-D for your Monitor 3, this excludes using the HDMI port. The Thunderbolt port is available, as is the VGA port. And VGA cables can run further than HDMI or DVI without boosting. There will be no problem for a 10ft+ run in your studio.

The Thunderbolt port, if I'm not wrong is compatible with a mDP (mini Display Port), so a mDP-HDMI or mDP-DVI adapter + a HDMI-HDMI or DVI-DVI cable would be required for Monitor 4.

Question then is what types of input does your Monitor 4 accept - VGA + HDMI? If VGA you are good with a VGA-VGA from mobo to Monitor. If HDMI, it would be a more expensive option to go VGA-HDMI as the VGA analog signal needs to be converted to the digital HDMI.

The other question is what length of cable is required for Monitor 4? If longer than 10ft, VGA is not a problem. HDMI and DVI limits are about 10-15ft (your mileage may vary, but I would not try longer than 15ft).

What Windows version are you using? Windows 7 is solid on multi-monitor support. XP was ok too. Not sure of Vista. Windows 10 has problems with multi-output DirectX 3D full screen rendering which, I think, is not related to your usage.

Mirroring with Windows, however, is limited to 2 monitors. If you want to try 3 monitor mirroring, try doing it with your motherboard graphics software - Intel Graphics Accelerator - but this would mean re-configuring your connections and monitors such that the onboard gfx is hooked to 3 monitors, and the expensive ASUS uses only one monitor.
 
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You wrote:
"...Is there a way to look up exact model of graphic card other than on the box? My box is too far under other boxes in the storage. My card has DVI-I and DVI-D, HDMI and full DP."

Google for 'ASUS HD7850"...and choose the ASUS site. There, type HD7850 in Search. There are 5 versions, and if yours has 2 DVI ports, looks like either the HD7850-DC2T-2GD5-V2 or the HD7850-DC2-2GD5-V2, or HD7850-DC-1GD5.

"The 2560x1080 monitors require dual link to run, also I think it looks the same with DVI-I and DVI-D, it just forces me to switch to DVI-D from I when HDMI connected."

Sorry I am not familiar with a dual-link DVI connection. Does this mean you have to use both DVI ports (DVI-D and DVI-I) to connect to one monitor, whilst the other monitor uses HDMI-HDMI? That would explain why you have to use DP-HDMI for the 4th monitor.

If the DVI-I port is available, the packaging says it comes with a DVI to D-sub adapter (VGA). Then use this to connect DVI-I to VGA into Monitor 4.

Not sure why the DP-HDMI does not work as they are both digital signals. Could be a bad cable (not uncommon). Disconnect the other connections and try only this DP-HDMI. If it works, the cable is fine, and means using the other connections deactivates the DP-HDMI. At a guess, it could also mean your card is limited to only 3 digital signals (dual-link + 1 more; or 3 single-links).

One last possible solution is to buy another graphic card...but this not as simple as it sounds unless you get the same or similar type of card as your present one. In other words, you only need one driver installed in Windows to drive the two cards, plus of course the built-in Windows generic VGA driver for the on-board gfx.

In such case, you should check the driver you are presently using for the ASUS before you buy. If it is a legacy driver, then you need a card that uses the same driver. I have tried installing a legacy and a more current driver together, and Windows rejects the installation. More headaches!
 
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Solution
Thank you for all your help. Dual link DVI just has more pins on the cable.
I was able to make 4 monitors work by connecting 4th monitor via VGA to VGA on motherboard graphics. And I did have long enough VGA cable. So this is great- it is working. I can not split desktop to 3 monitors. Another problem is that I had few unplanned restarts and a blue screen... Will continue to monitor. Thank you again for all the help.
 
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The onboard memory has a specified limit from a dropdown list. Could be 512 or 1024MB and is shared from your system memory, in your case 32GB.

According to the manual :
Advanced > System Agent Configuration > Graphics Configuration
 
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