How to split DVI?

[James Steele]

Question for any Mac savvy folks:

I have two monitors on my MAC. A 30" cinema as my primary and 23" cinema display as my secondary monitor. They're the older style monitors so they're DVI. The 30" is connected to the dual-link DVI connector on my ATI 5770 card. The 23" is connected to the DisplayPort connector with a passive DisplayPort to DVI adapter.

What I want to do is split the signal before it goes to the 23" monitor, with one output going to my secondary monitor in the control room, and then same output going out to another monitor in the studio.

I'm thinking I'd probably need an active DVI splitter that will take in incoming DVI signal and split it into two identical outputs. I'd also need about a 50' DVI cable to run out to the monitor in the studio. Has anybody done this? Anything to look out for? I do also have my old Dell 30" and if it's possible, I suppose I could split the dual-link DVI output and do the same thing and have a 30" out in the studio, but then I'd need a 50' dual-link DVI cable. I've found out that regular DVI cables do not work with dual-link monitors. You must have a dual-link cable.

[James Steele]

Never mind!!! I am in LUCK!!!

I have a ATI 5770 graphics card and I discovered I CAN run 3 monitors off of it, with some disclaimers: if you want to use 3 monitors you must use at least 2 ACTIVE DisplayPort to DVI adapters. DisplayPort to VGA counts as active.

At first I tried this:

ATI 5770 Connectors:
DualLink DVI --> Apple 30" Cinema Display
DisplayPort 1 --> Passive DP to DVI adapter --> Apple 23" Cinema Display
DisplayPort 2 --> DP to VGA adapter --> HP 24" w2408 monitor

In this case above, both the smaller monitors connected to the DisplayPort outputs worked but the 30" Cinema did not come on.

The solution was this:

ATI 5770 Connectors:
DualLink DVI --> Apple 30" Cinema Display
DisplayPort 1 --> ACTIVE DP to DVI adapter --> Apple 23" Cinema Display
DisplayPort 2 --> DP to VGA adapter --> HP 24" w2408 monitor

All 3 monitors came up. I then set the HP monitor to mirror the Apple 23" monitor and there I am! No extra stuff to buy and I can run a 50' VGA cable I already owned out into the studio! I just need to make a screen set where the main TOV is on the secondary display, invoke that out in the studio. I also changed back the option to have the menu on every monitor. If it bugs me, I'll just use SwitchResX and make a display set that changes which monitor is primary.