Triple head display on Power Mac G5 (three monitors)

Question

Triple head display on Power Mac G5 (three monitors)

Hi,

I have a PowerMac G5 with the AGP 8x Pro slot and the nVidia GeForce FX 5200 (ADC + DVI) card. I also have encountered a windfall of 19" Dell 1280x1024 displays.

I would like to concatenate 3 of these monitors each in portrait mode, so that the total display is 3072x1280 (WxH). In fact, I'd even be ok reducing resolution by 2x and going with 1536x640. Is there any way to do this on a Mac? It's quite easy to do on a PC. Matrox has some nice products (Parhelia and P750) that support 3 monitors and present a single virtual display to the OS, but Matrox appears to have no Mac driver support.

Here are my "requirements":
(1) Triple head display (of 3 identical monitors).
(2) Portrait mode for individual monitors (landscape for the whole thing).
(3) Ability to play a single video across all three (crucial).
(4) Single virtual monitor (not crucial).

I've verified that Macs can play a video across two displays with no problem. What I don't know is if this is possible if the different monitors are driven by two different video cards.

Please share any experience or suggestions running 3 or more monitors on a mac and your ability to play video across them.

Thanks!
David

PowerMac G5, Mac OS X (10.4.7)

Posted on Jul 29, 2006 11:14 AM

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Answer 1

Jul 29, 2006 5:05 PM in response to David Martin9

You'll have sync problems playing video across multiple cards. You need some sort of external device that will take your video signal and output it to multiple monitors.

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Answer 2

Jul 30, 2006 2:42 PM in response to Edwin Sneller

There is no triple headed card for Macs. You would need to use 2 @ ATI cards anyhow as they are only ones to support rotation.

So a 96/9800 in your AGP slot and a 7000/9200 PCI in a PCI slot. This WOULD allow you to run 3 display in rotation mode and have your desktop run that way. You would be able to drag things across the three displays. However, as the above poster states, there is just no way to do this and run video across all 3 and have it be smooth.

2/3 of your screen would be drawn by an AGP device with main-line access to RAM and running at 8x AGP speed, or likely 16 times the PCI bus speed. And also on the PCI bus are a variety of other devices chattering away, which the PCI card must wait in line for.

Not to mention the fact that since no one has brought out a CI & QE compatable PCI card for Macs, the PCI & AGP cards are thus using a completely different desktop rendering system, with the PCI card leaning far more heavily on the CPU; right when it is decoding video, a tough thing to begin with.

So, again as stated above, you would need an outside device that would take one large rendered image from your Mac GPU and split it across your screens.

I know the Matrox thing you are talking about. It is very cool, very VR. And ATI & Nvidia are quite busy denying that it has any use in the modern world. (Called "not invented here" syndrome) I think it's pretty obvious that it is the way things will eventual go, but with the 2 biggies having their heels dug in, don't expect it soon on a Mac.

Also, the Matrox thing works on games, but only ones written for it I think. I think there was a list of specific ones it worked with, but this is from memory.

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Answer 3

Aug 1, 2006 10:03 AM in response to David Pirinelli

Thanks for the replies. I guess the answer is "no". I find this incredibly disappointing, one case where PCs win hands-down over the Mac 😟. I guess Apple's market share is just too small for Matrox to bother supporting Mac with these niche products.

dm

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Answer 4

Aug 1, 2006 10:41 AM in response to David Martin9

From a business perspective you have to weigh the market for your products before spending money to develop them. Probably 1% (or less) of potential buyers would ever consider running 3 monitors (especially these days when you could buy 2 24" or 30" displays and get better results than what 3 19" screens would give you), so why would a graphics company even bother with the effort.

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