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PCtoMac-change

macrumors member
Original poster
Feb 10, 2007
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0
I know Crossfire doesn't work on the Mac, but if you get 2 X1900XT's w/ a dual monitor set-up could it actually be better than X1900XT's in crossfire with a single 30"?

What I'm think is probably wrong, but each card is seperate and would do only the screen their connected to, right? So if you have each card running on a monitor at 1440*900(just a random reso); wouldn't that be better than a single "unit" running 2880*1800?

Sorry if it's really hard to understand. I tried to explain it the best I could :rolleyes: .
 

Lord Blackadder

macrumors P6
May 7, 2004
15,670
5,503
Sod off
Technically that would work, but the software to do it doesn't exist (for games at least), plus the display's frames would form an annoying line down the middle of the "screen".
 

PCtoMac-change

macrumors member
Original poster
Feb 10, 2007
67
0
you can't connect 1 monitor to 2 video cards, or at least not to my knowledge

Let me try this again. You can have 2 X1900XT's in your MP, since Crossfire doesn't exist on Mac's(yet); can't you connect each of the cards to one monitor...one GPU a piece? Giving you a high reso, but the each card is only doing a low res. Because of the dual-monitor set-up, Then you have each card doing 800*600, because you want a 1600*1200.

Wouldn't that be better than a X1900XT in Crossfire doing 25*16 on a 30"?
 

daveL

macrumors 68020
Jun 18, 2003
2,425
0
Montana
you can't connect 1 monitor to 2 video cards, or at least not to my knowledge

The OP said dual monitors, not 2 cards connected to a single monitor, working in tandem.

All I can say is the OP must have money to burn.
 

Erasmus

macrumors 68030
Jun 22, 2006
2,756
298
Australia
Um, I think I understand what you are on about, but that's just using multiple monitors isn't it? That will work fine in OSX for different applications... It's nothing new. Shove four X1900's in the Mac Pro, and you can probably run 8 30" ACD's.

I'm guessing you don't intend to game with this...

So, yeah, if you grabbed 2 X1900's, and connected a 23" monitor to both of them, you would have a nice canvas size. Two 1600x1200's does not equal a 3200x2400. It equals a 3200x1200. You need four screens for that.

So, yeah, two gpus running two screens should run better than crossfire running a screen that is twice as big. (30" is not twice as big as 15". It is four times as big.)
 

PCtoMac-change

macrumors member
Original poster
Feb 10, 2007
67
0
Um, I think I understand what you are on about, but that's just using multiple monitors isn't it? That will work fine in OSX for different applications... It's nothing new. Shove four X1900's in the Mac Pro, and you can probably run 8 30" ACD's.

I'm guessing you don't intend to game with this...

So, yeah, if you grabbed 2 X1900's, and connected a 23" monitor to both of them, you would have a nice canvas size. Two 1600x1200's does not equal a 3200x2400. It equals a 3200x1200. You need four screens for that.

So, yeah, two gpus running two screens should run better than crossfire running a screen that is twice as big. (30" is not twice as big as 15". It is four times as big.)

Yup, that was what I wanted to know. Thanks.
 

twoodcc

macrumors P6
Feb 3, 2005
15,307
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Um, I think I understand what you are on about, but that's just using multiple monitors isn't it? That will work fine in OSX for different applications... It's nothing new. Shove four X1900's in the Mac Pro, and you can probably run 8 30" ACD's.

I'm guessing you don't intend to game with this...

So, yeah, if you grabbed 2 X1900's, and connected a 23" monitor to both of them, you would have a nice canvas size. Two 1600x1200's does not equal a 3200x2400. It equals a 3200x1200. You need four screens for that.

So, yeah, two gpus running two screens should run better than crossfire running a screen that is twice as big. (30" is not twice as big as 15". It is four times as big.)

so you can make 2 screens the same as one big screen? how do you do this? do you have to have 2 cards, or can you just hook up 2 screens to one card?
 

Erasmus

macrumors 68030
Jun 22, 2006
2,756
298
Australia
so you can make 2 screens the same as one big screen? how do you do this? do you have to have 2 cards, or can you just hook up 2 screens to one card?

Yes... you can run 2 monitors off the same card... They have two ports after all... And so, if you can get two X1900's to work in the MP, I see no reason why you can't run screens off both of them. Have you never seen a computer run more than one screen? You move the mouse to the side of one screen, and it appears on the other. You can drag windows from one monitor to the other, stuff like that.

You will always have the problem of having the monitor frames in the middle of your screen, but if you need more screen space, I'm sure you won't complain.
 

apfhex

macrumors 68030
Aug 8, 2006
2,670
5
Northern California
Yeah, if you have two X1900s and one monitor on each, then each monitor would have a x1900 to itself. But depending on what you're doing (gaming??), you might just want to have two monitors connected to one X1900.
 

twoodcc

macrumors P6
Feb 3, 2005
15,307
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Right side of wrong
Yes... you can run 2 monitors off the same card... They have two ports after all... And so, if you can get two X1900's to work in the MP, I see no reason why you can't run screens off both of them. Have you never seen a computer run more than one screen? You move the mouse to the side of one screen, and it appears on the other. You can drag windows from one monitor to the other, stuff like that.

You will always have the problem of having the monitor frames in the middle of your screen, but if you need more screen space, I'm sure you won't complain.

i know you can have more than one monitor, but i mean have 2 monitors act as 1 monitor.

so one big resolution, the dock and menu bar goes across both screens, etc

is this possible?
 

Lord Blackadder

macrumors P6
May 7, 2004
15,670
5,503
Sod off
i know you can have more than one monitor, but i mean have 2 monitors act as 1 monitor.

so one big resolution, the dock and menu bar goes across both screens, etc

is this possible?

OS X can span across two screens, but games will not as far as I know - the OP's idea of having each card draw one half of the "screen" (in fact one display each, but half of the game's output) is not currently supported AFAIK.

Lord Flashheart said:
Sorry I can't answer your qustion, but on a different note - Lord Black Adder I live your name

Best comedy series ever. Period.
 

twoodcc

macrumors P6
Feb 3, 2005
15,307
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The dock and menu bar will only exist on one of the displays. You get to pick which one in System Preferences.

ok, so you really can't make 2 displays act as 1 big one then. which is what i figured.

so there is no way to take 2 x 30" displays and watch a movie that's spread across both screens?
 

daddywags214

macrumors regular
Sep 26, 2006
120
0
Vancouver, BC
I also wondered about this when I first got an ACD. It's too bad that you can't make the menu bar and dock go onto two screens. I think it'd be annoying, but I'm sure some people would find it useful. Now I have a Mac Pro and 2 23" ACDs running from a single x1900xt.
 

Nugget

Contributor
Nov 24, 2002
2,122
1,357
Tejas Hill Country
ok, so you really can't make 2 displays act as 1 big one then. which is what i figured.

No, you can, that's exactly how it works. One giant desktop workspace. It's just the dock and menu bar that are limited to a single display (which makes sense, really).

so there is no way to take 2 x 30" displays and watch a movie that's spread across both screens?

That would be an application decision. Quicktime player won't in full screen mode, but there's no technical reason why it wouldn't be possible. Maybe VLC could be convinced to do it. If you're watching a movie in a window you can drag the window so that half of it is on each display, so at that point it's just a matter of making is large enough to satisfy. The aspect ratio of two displays side-by-side certainly wouldn't be conducive to watching a movie, though. It'd be way too wide (or way too short depending on your outlook).
 

daddywags214

macrumors regular
Sep 26, 2006
120
0
Vancouver, BC
I mean QuickTime Pro/DVD Player won't spread a movie across 2 30s in full screen mode, but in theory you could drag the window from one screen to the other and watch it on both, but you'd have a nice helping of bezel down the middle.
 

daddywags214

macrumors regular
Sep 26, 2006
120
0
Vancouver, BC
The aspect ratio of two displays side-by-side certainly wouldn't be conducive to watching a movie, though. It'd be way too wide (or way too short depending on your outlook).

If you were watching a movie filmed in 2.35:1 it'd make it almost across 2 displays, since ACDs would be 3.2:1
Since Apple Cinema Displays are 16:10. :)
Cool eh?
 

bearbo

macrumors 68000
Jul 20, 2006
1,858
0
No, you can, that's exactly how it works. One giant desktop workspace. It's just the dock and menu bar that are limited to a single display (which makes sense, really).

but that's not one big screen, that's still 2. the OS doesn't recognize those two as one. just two that you can put together, side by side, on top of each other, or diagonally

if the OS recognize 2 30" as one, then it'd think it's a screen with res of 5120x1600 or something. then the menubar will go across, so does dock.
 

twoodcc

macrumors P6
Feb 3, 2005
15,307
26
Right side of wrong
but that's not one big screen, that's still 2. the OS doesn't recognize those two as one. just two that you can put together, side by side, on top of each other, or diagonally

if the OS recognize 2 30" as one, then it'd think it's a screen with res of 5120x1600 or something. then the menubar will go across, so does dock.

thank you. that was exactly my point :)
 
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