SLI Vs. Crossfire

[Cerri]

I asked for help in another thread for help building a new gaming rig, and had pretty much decided on an SLI setup (getting one card now, and adding a 2nd card to utilize the SLI at a later time), but reading some info on the Crossfires, now I don't know.

Could someone explain the main differences between the GeForce SLI setup, versus a Crossfire setup, and your opinions as to which is better?

All I can figure out for sure is if I went with a Crossfire setup, I'd need a Crossfire motherboard, and a Radeon card that it Crossfire compatible (assuming I wait until the Crossfire Edition cards come down in price to buy the 2nd card to complete the setup.

I know for the SLI setup the cards need to be a matched pair, and that the Crossfires don't, as long as the non-Crossfire Edition card is Crossfire compatible (looked like the range was the X800s and the X850s), but what I'm really looking to figure out is the main differences in performance in a gaming setting.

[aradon]

With CrossFire, ATI has seemingly done most - but not all - things better compared to NVIDIA's offering. ATI's CrossFire, for example, offers the freedom to choose different card configurations, such as the possibility to combine X800 with X850. CrossFire also offers more dual rendering modes and SuperAA to enhance picture quality. What's more, CrossFire supports all DirectX and OpenGL games.

Provided you have the matching motherboard, you can upgrade effortlessly to a CrossFire system with a second card. NVIDIA's SLI falls down here because it demands an absolutely identical second card. Some ATI fans will still be a little disappointed - they had expected that they would be able to combine any Radeon card without additional measures.

The only area where NVIDIA's SLI comes out ahead is its price. Given that the CrossFire Edition models are practically full-blown XT-PE variants, the X850 for one is comparatively pricey. If you already have a Radeon X850 Pro for $350, for example, you will have to add $460 for the X850 XT PE CrossFire option. So instead of paying $700 for two X850 Pros, you would hand over more than $800- without even being able to take advantage of the added performance of the second card (16 instead of 12 pipes). Owners of a fast X800 model will come off lighter. A target price of $299 (€279) for the 256-MB model and $249 (€229) for the 128-MB version of the X800 CrossFire Edition is comparatively good value compared with a Radeon X800 XT PE.

How ATI's CrossFire fares in direct comparison with NVIDIA's SLI must await the former's completion of hardware and drivers - apparently not far off now. Until then ATI will hopefully also decide to give users more options to influence the various CrossFire modes.

[rspassey]

CrossFire also offers more dual rendering modes and SuperAA to enhance picture quality. What's more, CrossFire supports all DirectX and OpenGL games.

Are you forgetting Nvidias SLI AA 16 and SLI 8 rendering?

[aradon]

No, but isnt SuperAA different to that?

Doubling of the FSAA factor without speed loss (compared to a single card). A maximum 12x AA or 14x AA (12x + 2xS) is possible.

Please correct me if im wrong :D

[Force Flow]

1) SLI is out in the market already and quite available.
2) crossfire hardware is still lacking out in the market. It'll take some time before it's *actually* available.

As much as I am looking forward to crossfire, I have to say it's still more-or-less in the theoretical/preliminary stages of market readiness.

[aradon]

1) SLI is out in the market already and quite available.
2) crossfire hardware is still lacking out in the market. It'll take some time before it's *actually* available.

As much as I am looking forward to crossfire, I have to say it's still more-or-less in the theoretical/preliminary stages of market readiness.

True but it is totally available if you are happy with the x850/800 cards, i myself am not and will get the x1800 XT and wait for the X-Fire version.

[Cerri]

Thanks for all the info. :)

I'm not planning on building this new rig until somewhere between January and March of next year, so I've got time to decide yet, as well as time for Crossfire tech to fully be brought onto the market.

I'm not too worried about factoring the price of the Crossfire Edition cards right now into my decision, since I'll only be putting in one card when I do the build.

I'm figuring I'd get a Crossfire compatible X800 or X850 of some sort (if I decide to go with a Crossfire configuration instead of SLI), and add the Crossfire Edition card after about a year, at which point prices will most likely have come down. :)

[rspassey]

Nvidia also has pioneered the dual video card technology and cast it out into the market. In a sense you can say that Nvidia has developed the entire realm of rendering with dual cards. I am not trying to push Nvidia SLI becuase I have an SLI rig myself, but I am saying that Nvidia started it, they know it, and SLI works. There is also a huge variety of SLI ready cards, from 128mb to 512mb from 6600s to 7800gtx, and many vendors are making and selling SLI ready cards. Though Crossfire appears to be promising, its limited to a few cards from the get go, and Nvidia can always stay one step ahead, such as the release of newer and better drivers, newer and better lines of cards, and newer and better applications tailored for SLI. Plus, there are already a lot of games which are proven to perform better with SLI, this has been tested, and SLI drivers are made to optimize these games.
I would continue on, but I think I have made my point. For the moment, SLI certainly is one step ahead, and it appears that it will stay that way

[blue60007]

The main thing I'd be worried about is the fact that SLI is more developed and matured, while Crossfire is still in it's beginning stages.

[aradon]

Nvidia also has pioneered the dual video card technology and cast it out into the market. In a sense you can say that Nvidia has developed the entire realm of rendering with dual cards. I am not trying to push Nvidia SLI becuase I have an SLI rig myself, but I am saying that Nvidia started it, they know it, and SLI works. There is also a huge variety of SLI ready cards, from 128mb to 512mb from 6600s to 7800gtx, and many vendors are making and selling SLI ready cards. Though Crossfire appears to be promising, its limited to a few cards from the get go, and Nvidia can always stay one step ahead, such as the release of newer and better drivers, newer and better lines of cards, and newer and better applications tailored for SLI. Plus, there are already a lot of games which are proven to perform better with SLI, this has been tested, and SLI drivers are made to optimize these games.
I would continue on, but I think I have made my point. For the moment, SLI certainly is one step ahead, and it appears that it will stay that way

True but, nVidia releasing thing before ATI gives ATI the advantage as they know where to aim for the next product.

Also the very same argument can be given to Intel, end of the day they both do the job very well and generally, these days, the only difference is the price TBH.

[Cerri]

The thing that worries me the most about an SLI setup in my case, is that I won't be adding a 2nd card for at least 6-9 months and probably closer to 12, after I build the computer. SLI requires two cards that are exactly identical, including the BIOS.

I'm more worried I won't be able to find the identical card a year after I build the computer, and I definitely don't want to have to buy two new cards when I'm ready.

It'd be less of a problem with the Crossfire setup, since I only need a Crossfire-compatible card (the ones I'm looking at, the X1800XL or X1800XT) would do that easily, and by the time I'm ready for a 2nd card, I would imagine there'll be plenty of driver support/better and cheaper Crossfire Edition cards, etc.

I guess it's kind of a "6 of one, half dozen of the other" situation, heh. Seems like there's pros and cons with both setups, guess I'll just have to figure out which pros I want most, and which cons I can live with. *chuckle*

[RazorDX]

Check out Tomshardware.com. There is a huge in-depth explaination of both crossfire and SLI, breaking them both down as to how they work and how effective they really can be. A good read, it explains AA and everything.

[rspassey]

You shouldn't have trouble finding your card a year later, three year old cards are still produced and distributed, mydual 6800s have been available for probably over a year, and will continue to be available for lots longer.