dual graphics cards, dual monitors, ati crossfireX

[socrgy9]

i have 2 ati radeon hd 4850's. right now they are connected with the crossfirex bridges and i'm only using one monitor and running crossfirex. i'm thinking of getting a second monitor for better gaming/seeing more stuff in flight sim X.

what i can't find is how to use 2 monitors with 2 cards. do i remove the crossfirex bridges and connect one monitor per card, or do i keep the crossfirex bridges and connect both monitors to the first card, still running crossfirex?

thanks!

 

[paulpicks21]

I would just connect the 2 monitors to the one card and then extend the desktop using either desktop properties or Catalyst control center.

 

[socrgy9]

So u'd leave the crossfirex bridges connecting the two cards and keep crossfirex enabled, and just hook both monitors to the same card.

Thing is, I don't know if it would be more beneficial if both cards were runnin seperately, or do the cards work better if they're crossfired? Which configuration works better?

 

[paulpicks21]

Yes I would leave them connected with crossfire enabled and connect both monitors to the one card.

You will still get the added performance of crossfire that way.

 

[socrgy9]

So, running the cards in crossfirex is better performance than running them seperately? I wouldn't have expected that.

 

[smarteyeball]

So, running the cards in crossfirex is better performance than running them seperately? I wouldn't have expected that.

Ostensibly, the whole idea of multi-card gaming is to have two or more cards acting in concert as one, more powerful card. This is what creates the extra performance derived from crossfirex. The same applies to nvida's SLI technology.

To allow for the increased bandwidth of data flowing back and forth from both cards, a bridge that can carry more data is required. Without the bridge, the cards cannot communicate effectively enough with other to act in crossfirex mode.


Theoretically, 2 cards connected = double the performance. In reality, the performance increase is much less and varied.



Just keep in mind that since eyefinity is unavailable; for FSX and 4850's, you will have to run FSX in windowed mode. This hurts performance.

(I never managed to get FSX, 4850CF and two monitors working in fullscreen back in the day)

Best of luck.

 

[hunuok]

As mentioned, leave the crossfire connected and hook up the monitors to a single card. I had mine on separate cards to "even out" the load (probably a psychological thing).

Performance wise, don't expect to get double the performance. Make sure you install latest drivers, although I imagine ATI dropped the ball with 4xxx series drivers.

Also, having a second monitor will mean important data(ex crosshairs in FPS) are split between bezels, rendering games difficult to play. Hence, the three monitor setups. For three monitor setups, you will also need an ATI certified Eyefinity displayport adapter.

Good luck.