Multi screen with single workstation

[Lawrence]

Dear All,

 

I have a very strange situation: I has 8 sets of HP Z620 with AMD ATI HD7970 which were purchased more than 3 years ago for a Watchout show, that show lasted for 1 year without any problem and then were store for 2 years, Recently we take out and reinstall the OS (win7 32-bit, using HP recovery CD) for another new project, however, I have trouble to output more than 2 video channel per workstation. HP Z620 is running with 800W power supply and HD7970 only requires 230W. HD7970 should run with 4 displays, which we confirmed that 3 years ago. At first we were thinking it is extender problem but we tried with same problem with direct cable (2m in length). We were able to output 2 video channels but the 3rd display is unstable. At windows level, for those mini-dp connection, windows only identify them as generic monitor. Only either HDMI or DVI can use but sometimes it is unstable, windows detect there is a display but unable to set resolution or output video to the 3rd channel.

 

We have used the same display driver as 3yrs ago, and then also use windows update to update to the latest plus the graphics driver. We also change OS to Win7 64-bit (english) and result is the same. Tested the same machine with ASUS Nvidia GTX 670, 660Ti and 770, and they all cannot output the 3rd display.

 

I also suspect it is power issue but if I unplug one of the power cable (6 pin or 8 pin) then HP will not able to power on, screen prompt me to insert both 6 and 8 pin power, so seems graphics card knows if there enough power.

 

Is anyone has similar experience before? Do you know any window tools that can check the graphics card power usage (maybe HP power supply unstable after 3 years?) or any tools can check if the PCI-e slot is running at x16 Gen3?

 

Regards,

 

Lawrence

[paolino]

Hi,

usually the problem can only have two motives,

EDID or Display port adapter not active.

 

1) connect the output to a recent monitor or try to use EDID Emulator

2) you "MUST USE" DISPLAY PORT/DVI active adapter ( I use Sapphire 44000-02-40r )

 

Paolino

[Morgan Wong]

are you using ACTIVE display port to DVI/VGA adapter?

some model of HD7970 can run up to 6 outputs,

I believe HD7970 require ACTIVE adapter for 3rd or more output.

 

 

M.

 

[Lawrence]

Dear Paolino and Morgan,

 

Thanks for your suggestions, as explained before, the whole setup was used 3 years before without problem, I used the active mini-dp adaptor that I used 3 years ago as well..... there are 8 sets of them and 1 was broken.... I don't believe all 7 sets will be broken. Besides, if they are broken, I supposed it will be total failure? I do able to obtain 2 output from 2 mini-dp from the same card, just the 3rd (DVI or HDMI) is unstable.

 

In addition, Nvidia card doesn't require any active dp adaptor, still doesn't produce stable signal for the 3rd video channels, and I have tested 3 different cards with different model. It seems to be the workstation issue but I have 8 sets of them, all have the same problem? Some setting must be wrong that I didn't notice!

 

The projectors are new - 4 sets of optoma GT1080 on one card via Kramer cat5 extender; the testing platform is normal Dell monitor that I used for 4~6 years ago via direct DVI cable.

 

I also suspect EDID problem but both Kramer extender is EDID pass-thru, can you suggest a good EDID emulator on Win7 32-bit? Thanks in advance!

 

Regards,

 

Lawrence

[paolino]

Hi Lawrence,

 

I normally use Lindy model 32106 or  Extron EDID 101D.

 

Paolino