Help Understanding SLI & Crossfire Options

[RDuke]

I have the Asus A8N32-SLI motherboard, and it's currently populated with a single ATI X1800XL video card. Could I add, say, the new ATI X1900 XT and bridge them together? Would this setup work OK; or do I need to buy a Crossfire "master card"? I'd like to keep the existing X1800XL, and add one new card. What are the options?

Thanks a lot,
Duke

 

[kuyaglen]

no.

For Crossfire you need a crossfire mobo. That Asus board is SLI. And if you did have a Crossfire board, make sure one of your video cards is a Crossfire Master card.

Though I am curious about performance differences between:
Master 1900 + Slave 1800
vs
Master 1800 + Slave 1900

 

[RDuke]

no.

thanks for the quick reply, kuyaglen. The X1800XL card has the bridge connector on it, so there must be some combination for running two boards simultaneously, no? Are you saying that the only option I have is to buy an identical X1800XL board to run dual? My motherboard has two PCI-E video slots.

Duke

 

[Astaroth125]

He is saying that no configuration of dual ATi graphics cards working in tandem is possible. There is a lock to prevent you from running Crossfire on your motherboard. To keep your existing video card, and add a second video card, you would need a different motherboard, which suports Crossfire, and the X1800 mastercard.

Astaroth

 

[pibrahim]

Regardless of the fact that two ATI cards won't run on an SLI motherboard...

...why would you pair up a 1900XT with an 1800XL? It's just a waste. If you want to go crossfire, get the master card for the 1800 series - don't bother paying more for the 1900 series because, I believe I'm correct in saying, your 1800XL will only slow it down anyway.

 

[RDuke]

He is saying that no configuration of dual ATi graphics cards working in tandem is possible. There is a lock to prevent you from running Crossfire on your motherboard. To keep your existing video card, and add a second video card, you would need a different motherboard, which suports Crossfire, and the X1800 mastercard.
Astaroth

thanks, Astaroth - The thing that's confusing me is the fact that my motherboard has two PCI-E video card slots; yet I'm hearing that it isn't possible to run two video cards in any combination, because the m/b is SLI and not Cross-fire.

Duke

 

[BigJavy]

thanks, Astaroth - The thing that's confusing me is the fact that my motherboard has two PCI-E video card slots; yet I'm hearing that it isn't possible to run two video cards in any combination, because the m/b is SLI and not Cross-fire.

Duke

SLI and Crossfire are two different things (obviously - SLI = nvidia, Crossfire = ATI). You have an SLI motherboard, not a crossfire motherboard, therefore, you can only use an SLI (nvidia) setup. If you wanted to go crossfire, you'd need a crossfire mastercard AND a crossfire motherboard like
this .

But like others have said, you'd be wasting your time w/ a 1900/1800 setup. You'd probably be better off just investing in a 7800gt/gtx card now and adding another one later or buying one 1900 or something like that. You've got lotsa options... crossfire just isn't one of them w/ your mobo.

 

[RDuke]

SLI and Crossfire are two different things (obviously - SLI = nvidia, Crossfire = ATI). You have an SLI motherboard, not a crossfire motherboard, therefore, you can only use an SLI (nvidia) setup. ....

Oh, now I see. Thanks, BigJavy, you've helped clear up my mis-understanding regarding the differences between SLI and Crossfire.

Cheers,
Duke

 

[Brent_Justice]

You cannot crossfire X1900 and X1800, if you want a dual X1800 series setup you need the X1800 XL or XT and the X1800 CrossFire Edition Master Card. If you want dual X1900's you need an X1900 XT or XTX and the X1900 XT CrossFire Edition Master Card.

 

[Lord of Shadows]

Sounds so easy! ;o)

 

[BigJavy]

You cannot crossfire X1900 and X1800,

Is that something they're working on? Making it so you can mix cards (or generations of cards)? Don't really know that much about xfire.

 

[Brent_Justice]

Is that something they're working on? Making it so you can mix cards (or generations of cards)? Don't really know that much about xfire.

It is something neither ATI nor NVIDIA supports at this time

 

[iJeff]

You cannot crossfire X1900 and X1800, if you want a dual X1800 series setup you need the X1800 XL or XT and the X1800 CrossFire Edition Master Card. If you want dual X1900's you need an X1900 XT or XTX and the X1900 XT CrossFire Edition Master Card.

Are you sure? I remember reading somewhere that even older cards (such as my x800xl) would work with crossfire. Do they just have to be of the same series? (By series I mean 1800's, 1900's, 800's, etc)

 

[heatlesssun]

You can only CrossFire two cards with the same GPU. This is in ATI FAQ on their CrossFire site.

As far as an SLI/CrossFire motherboard, there's no technical reason why it can't be done from what I understand. I heard that the new 975 Intel mobo can do it, it supports CrossFire, and can work with SLI as well, but is not supported by nVidia.

Someone will no doubt do it officially, but I doubt that ATI or nVidia will support it.