Problems running 2 monitors....long cable.
by Xavier de Champs on Nov 15, 2010 at 11:43:39 pm
Have a Mac Pro Late 2009. With the ATI Radeon 4870 Graphics Card.
The card has one DVI output and one Mini Displayport output.
I have been running a single Eizo monitor at 1920x1200 no problem for a year. Using the DVI output.
Now I bought a second Eizo monitor with same resolution, but not exactly the same series. This too can run at 1920x1200 natively.
Bought a Mini Displayport to DVI adapter, and hooked the second montir up. I get static. Picture is there, but only for 1/4 second, and then static like in the old days on the TV, just sharper and more detailed static.
I am able to run this monitor with a Mini Displayport to VGA adapter, but not at its native res. Lower..at 16XX something.
One very important notice is, that I´m running both my DVI cables 10 meters (32 feet). Which is long, but it has always worked with my older setup. And through several PC setups, through the years.
I've tried running half distance, and still get the static. (4 meters - 15 feet). Then I tried just hooking directly via adapter and short DVI cable (1 meter or so). Worked.
So...the problem is with the Mini Displayport. Is it not possible to run this long distances with the Mini Displayport (converted to DVI)? I´ve tried both with Single and Dual link?
Is the DVI output on the ATI card stronger? Stronger signal?
My new screen also has a Displayport input (not Mini). Would it be better to run a Mini-displayport to Max-displayport cable this distance?
What are my options? I can move my computer closer, maybe to 15 feet, but I would rather find another solition if there is any.
Lots of info and noise on this question, I know. But maybe someone recognizes the problem, and has a solution.
Re: Problems running 2 monitors....long cable. by John Davidson on Nov 16, 2010 at 12:56:43 am
This is basically the same issue people with older mac pros have had with the new 27 cinema displays. You either have to stay mini-display to display (I have run extensions to two 27' with no problem on a new mac pro) or buy some kind of $150 converter to go from mini-display to to DVI. The simple adapter won't work.