[bearcat2000]

Hi everyone,
I just got my Dual 2 and am using dual monitors. It came with an ATI 9600 with 64MB which supports 2 monitors and that's how I'm using it now. However, I do have a ATI 9000 Pro with 64MB as well. Would I get better performance using one card per monitor over using both on the ATI 9600 now? Obviously the 9600 is a faster card in general. I just didn't know if each monitor had 64MB if that would make more of a diff. Any knowledge on this would be greatly appreciated. Thanks!!! Bearcat

[Spliffdaddy]

Since both cards have an AGP (accelerated graphics port) interface and there's only one available AGP slot in the machine - you can't use both cards at the same time.

You could use an AGP-interface card along with a PCI-interface card (peripheral component interconnect)...but there are very few PCI video cards (that don't suck) to choose from - because PCI interface is slower than AGP.

Having one graphic processing unit (GPU) per monitor is better than sharing one GPU between 2 monitors - so you had the right idea...but the video card you already have will do just fine driving 2 monitors.

[Maharaja]

Aslo to add bearcat2000's question,

If i hook up two displays to a single video card, i assume that the VRAM would be split between the two right? would this affect performance?

Thanks.

[djohnson]

Originally posted by Maharaja:
Aslo to add bearcat2000's question,

If i hook up two displays to a single video card, i assume that the VRAM would be split between the two right? would this affect performance?

Thanks.

Yes it will.

[Tenacious Dyl]

a more detailed question... will it simply be split and used accordingly? For example...


(with a 64 meg card)
Monitor A: up to 32 megs
Monitor B: up to 32 megs

or would it be...

(with a 64 meg card)
Monitor A: (whatever it uses of the 64 and capped at its usage + other when = to 64)
Monitor B: (what ever it uses of the 64 and capped at its usage + other when = to 64)

please let me know as i use duals like mad I assume its my second guess.. but not sure

[blakespot]

You definitely want to use both screens on one AGP card. When you game fullscreen in 3D, it only is on one screen at a time so the 2nd screen on that card won't slow you down - and the card can handle desktop gfx so easily that two screens does not even begin to tax it.

Reasons not to use PCI as 2nd monitor card:

- PCI slower than AGP
- Video will saturate PCI bus, slowing other peripherals
- You will lose Quartz Extreme, which uses 3D hardware to do 2D desktop gfx
- Why let the 2nd monitor port on that Raden lie dormant?

This is a no brainer - your are FAR better off using 1 card.





blakespot

[reader50]

How about us crazy ones who lust after three monitors?

ps - if you do not use the PCI bus for high-bandwidth peripherals, then there is no penalty for turning on the PCI QE hack.

[GoGoReggieXPowars]

Originally posted by Tenacious Dyl:
a more detailed question... will it simply be split and used accordingly? For example...


(with a 64 meg card)
Monitor A: up to 32 megs
Monitor B: up to 32 megs

It's an even split, each monitor gets 32 Megs.

[Tenacious Dyl]

so this means that if im not in a single monitor full screen game, and say, im watching a dvd in one window, and some other stuff in anotehr, with lots of effects, or visual things... that if the LEFT monitor say, uses 10 megs, and the right NEEDS 40 (which it has enough for) it will cap it at 32 and start lagging, despite having 54 megs open total?!

[osxisfun]

yes. ati will have an inexpensive PCI card out soon. that's exactly why i want to buy one. currently i drive 2 apple 20" off my default g5 dual 2.0 card.

my hope is that more vram dedicated to each monitor will improve expose performance.

[AngryAngel]

Although the ATI control panel clearly says that my ATI 9600pro 64MB is split into 32MB on each of my two 19" monitors, when I tested UT2003 I got exactly the same frame rates with dual monitors (one displaying the game, the other just showing open finder windows, etc.) as when I restarted with only one plugged in (and the ATI control panel said 64MB for that monitor).

It might be that even 32MB wasn't small enough to be the limiting factor for frame rates (this is a G5 1.6 with 2GB RAM).

[Cadaver]

Virtually all games will run on the main display only (the second goes black), releasing all the VRAM for the single display.

Forcing a game into a windowed mode so you can still use your desktop on the other monitor will kill its performance from a multitude of reasons.

If you really worry about VRAM, get yourself a Radeon 9800 Special Edition (256MB total or 128MB per display).