Sli and ATI...?

[Darth Revan]

I'd heard that you can only run two Nvidia card with sli, ex: 2x 7800's. Is that true or could I say run 2x X850xts with SLI?
Thx

[rspassey]

Only Nvidia's.

[Dark Nova]

ATI dont run sli. youll have to take Nvidia

[kstatefan40]

ATI is developing a similar technology called Crossfire. It is still in development, so you will have to wait until it is out to run dual ATI cards

[blue60007]

I remember reading that crossfire able video cards are going to be released very soon (like this month) and crossfire mobos shortly there after. I think it was in a pcmech headline. Here it is:

http://www.theregister.com/2005/09/1...crossfire_sli/

It says next week...so I guess we'll see

[rspassey]

I cant wait to see the bench mark tests of cross fire vs SLI. Should be interesting, I might have to shove out the money and build myelf one too, just to see .

[ComputerNut]

Out of curiosity, shoud I assume that cross-fire wont work with SLi type boards? (ie, A8N-SLI)

CN

[Darth Revan]

Thx for the quick replys guy, guess I'm gonna look at the Nvdia line this time.
Thx

[blue60007]

Originally Posted by ComputerNut Out of curiosity, shoud I assume that cross-fire wont work with SLi type boards? (ie, A8N-SLI) CN

Intel's 975X chipset, the upcoming successor to today's 955X, will support Nvidia's SLi technology and the ATI equivalent, CrossFire.

Your example won't work with crossfire, but it sounds like any motherboard equipped wit the 975X chipset will support SLi and Crossfire.

I cant wait to see the bench mark tests of cross fire vs SLI. Should be interesting, I might have to shove out the money and build myelf one too, just to see .

I think ATi's Crossfire will be far superior to SLI, for a few reasons. After reading the info on Crossfire at ww.ati.com, you will have to have one video card that is the "Crossfire Edition" version of the series (There will be a X850 Crossfire Edition, and a X800 Crossfire Edition version; and note that these are PIC-E only) as the primary processor. This can be used alone if you like. This card also has a chipset on the video card that coordinates the workload division, this is called the "compositing engine", and puts the images together to assemble the final frame and output. This is opposed to SLi, where this is built into the nForce4 chipset, which is located off the video card. Then to make the system dual video card, all you have to do is throw in any standard version of the video card from the same series (ie, any X800 version can be used with the X800 "Crossfire Edition" card, and the same goes for X850). This is nice, because to upgrade your standard PCI-E X8xx card to Crossfire, you just need a new motherboard, and a "Crossfire Edition" card (oh and the ever important Crossfire certified PSU), and you can still use your old card with the new one. No need to buy two new cards.

The two cards will be "bridged" by an external cable. This cable goes from the co-GPU's DVI output, to a DMS input on the main GPU (the "Crossfire Edition" one), the partially render image that comes through the DVI link, will be combined by the "compositing engine" and then sent through the main card's output to your monitor. There are two different ways the two cards will work together to render frames, one is "Scissor" and the other is "Supertiling", I'm not sure what scissor does, but supertiling I believe splits the scene into 16 tiles for each GPU to render, to better distribute the workload.

EDIT: I incorrectly referred to the X8xx version cards that will enable Crossfire as "Crossfire Ready", which is wrong, "Crossfire Ready" cards are PCI-E versions of the X800 and X850 series. The correct name for the cards that contain the "compositing engine" and DMS input (for connecting the two cards) is "Crossfire Edition". So if you have a X800 XT, then you will need a X800 Crossfire Edition card. (your original X800 is the "Crossfire Ready" card)

Should be correct above.

[rspassey]

If you already had an SLI ready graphics card, and there are so many as opposed to the two crossfire cards you say will be realeased, than all you need is another one of the same, and an sli mobo and an sli psu, the same exact thig you said about upgrading to crossfire.

[Jaggannath]

Looks like nVidia really has got the jump on ATi in this instance... ATi will need to offer more possible cards before it really becomes attractive I reckon