3 Monitors

[Maqqie]

Hey Guys,
I've got several questions. I am planning on having a 3 monitor setup with my new pc, which I plan to have two video cards running SLI. The thing is, I read, with two video cards running in SLI you can only attach ONE monitor to the four ports. I would have thought you'd at least be able to attach two monitors to the primary video card. Is this true?

Also since, I won't be able to attach 3 monitors to the video cards running in SLI mode, I've decided to get a seperate video card for the 3rd monitor. Can I use any video card for this? (I was thinking of a 7900GT for this.

Lastly, I've noticed with my current setup (two screens attached to ONE video card) that if I am watching a movie on one screen and I play a game on the other, the sound of the movie still plays but the image goes black. I am presumming this is because once the game starts all the video card's power is allocated to rendering the game. If I had an extra video card for the 3rd monitor, would I be able to play a game and watch a movie simultaneously?

Maqqie

[doctorgonzo]

Yes, you can only use SLI with one monitor. That's how it works.

If you do get a third card, you will probably need a PCI video card, since very few motherboards have 3 PCI-E x16 slots for video cards.

[Maqqie]

Originally Posted by doctorgonzo Yes, you can only use SLI with one monitor. That's how it works. If you do get a third card, you will probably need a PCI video card, since very few motherboards have 3 PCI-E x16 slots for video cards.

Thnx for replying Doctorgonzo. Can I use any video card for the 2nd & 3rd monitor (like the one suggested in my first post)?

Also, if I can a seperate video card for the 2nd & 3rd monitor, will I be able to watch movies and play games simlutaneously? (not that I'd want to, just asking)

[RJ]

There are also quad-head capable video cards out there, but I believe they're not really powerful for 3D.
So if you want the SLI power then I guess you do need an extra PCI video card for the 3rd monitor.

Lastly, I've noticed with my current setup (two screens attached to ONE video card) that if I am watching a movie on one screen and I play a game on the other, the sound of the movie still plays but the image goes black. I am presumming this is because once the game starts all the video card's power is allocated to rendering the game. If I had an extra video card for the 3rd monitor, would I be able to play a game and watch a movie simultaneously?

The black part is because of the overlay, which is normally used. The video area is black, and the overlay (which is a hardware chip on the video card itself) renders the image and puts it on top of the black area.
But even today's dual-head cards have only one overlay, so it can be assigned to only one monitor, and the other will just display the black area.

There are also possibilities to clone the overlay etc., but I don't know how it works on detail.

However, with SLI you should not have that problem as you have 2 video cards, and each has an overlay.
Also when adding the 3rd card, it will also have an overlay. So you should not experience that kind of problem.

RJ

[glc]

http://forum.pcmech.com/showthread.php?t=160400

Please don't start new threads for essentially the same issue. Thank you.

That said, the best way to run 3 monitors is with 2 video cards, at least one of which is dual head, and forego SLI - unless you buy a single triple or quad head card.