Creating Display Wall - Video Issue

[AnEbrahim]

Hello,

Admittedly, I don't know much about this stuff. I'm an undergraute who was hired in a research lab for the summer by a boss I told I had little computer experience but was willing to learn. This first display wall project has involved a lot of learning, and I would really appreciate any and all help regarding this issue.

I'm currently working on a project for work that involves creating a display wall from 12 46" Westinghouse LCDs (LD-4655VX). I was hired after this purchase was made, so I'm stuck working with these displays that only have 2 HDMI and 2 VGA ports each. The computer I'm putting together to run the display wall will have 2 AMD FirePro W600's, each with 6 mini-DisplayPorts. Today, I realized there may be an issue trying to connect all 12 displays to the computer. I've been on the phone most of the day talking to AMD. Two customer service representatives gave me 2 options to connect these displays to the graphics cards:

Option 1: Purchase a mini-DisplayPort to HDMI Active adapter, which is new on the market and not officially supported by AMD in their supported Eyefinity adapters list. The one I was looking at was from Kanex (http://www.kanexlive.com/mdphd10ft) but the problem here is that it's male HDMI and only 10 feet. This may work for the displays that are closest to the computer but the furthest displays may be approximately 32 feet away. If this is a viable option, I may also need a way to extend the HDMI portion another 20 feet. Is this even possible?

Option 2: Purchase 2 passive mini-DisplayPort to HDMI adapters and 4 active mini-DisplayPort to VGA adapters as each card can "passively" run 2. I spoke to Westinghouse, and the representive told me the VGA input could handle 1080p - seriously? I thought HD could only really be handled by digital and even then, running a VGA cable more than 15 feet is going to cause some problems, right? This option, in my opinion, doesn't seem like a good one.

Option 3: This is an option that I came up with as I've seen it work already with a computer running 3 displays. That is take a mini-DisplayPort to Active DVI adapter that is supported by AMD and then a DVI to HDMI adapter. I'll then carry the signal the rest of the way via HDMI. When I mentioned this to the guy at AMD, he said putting the DVI to HDMI adapter on it could counter the whole "active" ability of the first adapter.

If there are better options out there, please let me know. Any help, suggestions, or advice would be greatly appreciated. Thank you guys.

 

[somethingsketchy]

Depending on the budget for this video wall project, I'd say do Option #3. I have done a similar project (not as many monitors), and I had very good luck with the active mini-DisplayPort to DVI adapters.

Since most of our monitors in house had no HDMI inputs (only DVI), this was the only route we could take, without buying new monitors (prohibitive expensive). If you buy an active adapter that is supported by AMD, you will have much better luck.

 

[Knavish]

VGA connectors definitely handle high resolutions, but you may get a bit of noise / fuzziness since it's an analog signal. I ran a 22" CRT monitor at 2048x1536 on a VGA connector back around 10 yrs ago. You might run into trouble sending these high resolutions over a long VGA cable, though.

I had a project like yours when I was in grad school. We were using 50 LCD screens (at 1280x1024) and a rack of computers that was 100-200 feet away. We successfully used some DVI-to-CAT6 modulators to send the signals to the monitors. A similar device works for HDMI (At Monoprice). Maybe you can find them from a name-brand vendor, too.

I vote that you use mini-DisplayPort to HDMI for all your video card outputs, and then use these HDMI over CAT6 modulators to get the signal to your monitors. At ~$40 per extender, it's definitely worth a try!

One warning: we ran into problems using CAT5 for this type of modulator. DEFINITELY BUY CAT6 wire.

Let me know how it goes!

 

[AnEbrahim]

Sorry it's taken so long to reply. I really, really appreciate the advice.

Preferably, I'd like to see the mini-DisplayPort-HDMI ACTIVE adapter work as you suggested, Knavish. The particular adapter I'm looking at (http://www.kanexlive.com/mdphd10ft) will already give me about 10 feet and from what I read, they make compliant HDMI cables at 45 feet, although that's a length I won't need. About 20-25 feet will suffice. The CAT6 system would work for this, but I don't need to go that far so I may just tack on another HDMI cable that'll run the rest of the length.

But, let's say the mini-DisplayPort-HDMI ACTIVE adapter won't work as it's not supported by AMD's Eyefinity, then I think Somethingsketchy's advice is what I'm going to have to go to next. The only question I have here is was the customer service representative at AMD correct when he said the conversion of the signal (I suppose they call it the "clock" ?) by the mini-DisplayPort-DVI ACTIVE adapter would be countered by the addition of the male DVI to female HDMI adapter? This doesn't make sense to me - if the signal's already been altered by the ACTIVE adapter to go from DisplayPort "clock" to the HDMI/DVI/VGA "clock", why would the second adapter to merely change it from DVI to HDMI undo the changing of the signal by the active adapter?

Thanks again, guys.