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His radeon hd 7770 will only run two monitors

Last response: in Graphics & Displays
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April 14, 2012 7:16:38 PM

My HD 7770 will only run two monitors. The catalyst center will not even pick up the other monitor. Win 7 will at least detect it but will not allow me to save the settings to extend the desktop. It lists the Acer as Analogue even though I am using the DVI input. I am using two HP LP 2465 and one Acer AL2416WB (DVI-D). I have tried the following configurations:

HD 7770 Video Card DVI to HP LP 2465 (Monitor 1) DVI input
HD 7770 Video Card MiniDisplayport to HP LP 2465 (Monitor 2) DVI input

This configuration works great, but it is only two (2) monitors. It is when I plug in the third monitor that I have trouble. As soon as I plug in the third monitor, one of the two that are already working, suddenly goes black from a loss of signal. I am running Catalyst 12.3.

On the HD 7770 video card outs I have tried the:
DVI+MDP+MDP - only two monitors will work
DVI+MDP+HDMI - only two monitors will work

Could it be a product of the age of the monitors? If anyone has any ideas I am all ears.

Thanks for the help.
a b α HP
a b C Monitor
April 14, 2012 7:30:27 PM

With three monitors you don't want to use the HDMI port and you want to get a DVI cable with two ends so that you can connect two of the monitors with the DVI port and the third with the display port.

http://www.newegg.com/Product/Product.aspx?Item=N82E168...
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April 14, 2012 7:51:22 PM

Thanks, I will get one and let you know how it turns out. Ordering now.
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June 3, 2012 11:00:14 PM

inzone said:
With three monitors you don't want to use the HDMI port and you want to get a DVI cable with two ends so that you can connect two of the monitors with the DVI port and the third with the display port.

http://www.newegg.com/Product/Product.aspx?Item=N82E168...



Why is that? That makes no sense at all. Why bother manufacturing it with the ports if there are permutations that cannot be used, and the idea is to run multi monitors in the first place. I am running into the same problem, however my first mistake was likely purchasing from Best Buy. My suspicion is the need of a larger power supply.
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June 4, 2012 1:32:46 AM

arent there multiple different types of dvi conns also so how can u find the exact one u need
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June 4, 2012 1:49:12 AM

I believe I am getting to the bottom of this. If using 3 displays, at least one must be mini displayport compatible ... if not, then you must use an ACTIVE minidisplayport adaptor that is also approved by AMD to connect to your third display in whatever way you see fit (HDMI, DVI etc etc).
Passive adaptors will not work, and apparently some active adaptors will not either.

This is very frustrating, and a major black mark against RADEON if you ask me.
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March 14, 2013 4:26:26 AM

Hi,
Did you ever sort out your problem with the 3 monitors. I am havin ght e exact same problem now. Looking to by a display port to dvi adapter today. Did this resolve it for you.

Cheers
Brian

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June 18, 2013 8:08:42 AM

Hi guys, im having all the problems you are having but i have found out that if you use a display port to VGA adapter (very cheap too) it doesnt need to be active because there is something about the way vga works that it takes power from the display port, iv'e ordered mine today and ill get back to you on it, i have read alot of success stories on forums with this DP to VGA + 2 DVI setup!
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July 20, 2014 8:06:05 PM

I know this is an old thread, but lots of people are still having this issue. I have a Gigabyte HD 7770 card, and have been running three monitors for a couple of years. Two Dells with Display port to DVI passive cables, and a widescreen LG with DVI to DVI. Initially, I just plugged them in, it worked fine (Desktop on one monitor, extended to the other two) and it has worked fine ever since. However, I have just revamped the system into a new case with the same Motherboard, same Video card, same power supply, but different disk drive setup, so had to reload Windows (same setup disk, Win 7 64-bit). Now I can have any 2 of the 3 working but not all 3. I am wondering if the new updated drivers are the cause? Interestingly, the initial POST, and BIOS if entered, shows duplicated on monitors 1 and 2; the Starting Windows bit also shows duplicated on 1 and 2, but when Windows fully appears it is on 2 and 3. If I try to bring the third active through Screen Resolution or Catalyst Control Centre I get Unable to Save Display Settings. Sort that lot out!

Update - Just on a hunch, I tried the 32-bit drivers/Catalyst, no difference. I also notice than BOINC (Seti@Home, etc), is now showing 'Computation Error' on all the jobs which use GPU. It was fine last week.

Another update - 3 monitors working fine now, BOINC using GPU with no issues. I watched a video at http://support.amd.com/en-us/search/faq/154 which explains VGA/HDMI/DVI/Ports etc. Then on to
http://support.amd.com/en-us/download which has a link to Automatically Detect and Install. This seems to have fixed the problem. The latest Catalyst Control Centre (er?) from AMD site didn't work. I am using a DVI->DVI, DisplayPort->DVI, DisplayPort->DVI (all passive and cheap !!!!!). Smiley smiley.
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July 23, 2014 6:38:41 AM

I also have a HD7770 - I have 3 monitors working - but the 3rd one will only run @ 480x640, I want it to run at 1200x1600.
Can anyone help?

I have the following set-up:
1: 30" HP @ 2560x1600 : DVI --> DVI
2: 20" HP @ 1200x1600: DVI --> DVI
3: 20" HP @ 480x640 : Displayport (active adpater)--> DVI

I have the latest catalyst drivers in installed (windows 7 64bit).

Update:
So I just discovered this. I can have the 30" plugged into 1 of the dvi's and one of the 20"s plugged into the display via the active dvi adapter - and both will run at full res.
Thought I had solved because - whenever I have plugged a monitor directly in DVI-DVI it has always been detected and then run at full resolution fine..... this time..... nothing. Not even detected.
This is getting really annoying - this card is suppose to be able to take upto 6 displays!!!
Anyone???? Please????

Solved my issues:
Bit of strange one, but I swapped out one 20" monitors for a different one and now I have all 3 monitors working as they should:

1: 30" HP @ 2560x1600 : DVI --> DVI
2: 20" HP @ 1200x1600: DVI --> DVI
3: 20" HP @ 1200x1600: Displayport (+active DVI adapter)--> DVI

The "broken" 20" monitor when plugged into a single monitor system seemed to function normally. Odd, odd... very odd.
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