SLI vs Crossfire

[Versus3k]

Hi all

In the next month I will be upgrading my computer and although I understand future-proofing a PC is a difficult one, I’m looking at dual GPU as one way to extend the life of the computer. This way I can use one graphics card now and then in the future buy another to boost the performance when future games become more demanding.

The problem is which technology to go for?

On the one hand I can get an SLI ready motherboard now, buy an NVIDIA card, and then get another identical card at a later date. But will it be possible to get an identical card in 6 months time? (Rumour has it that NVIDIA may be unlocking the identical card requirement, but I'm not sure where I heard that)

On the other hand, ATI will be introducing Crossfire soon and this technology is not limited to having two identical cards (only the same flavour). And apparently it will have more modes, one of which will allow non-dual GPU ready games to utilise dual GPU. But at present I am unable to find any Crossfire motherboards for sale (in the UK), so I’d have to wait.

Anyway, this is my limited understanding of both technologies and I'd like to know what you guys think.

BTW My new rig will mainly be for BF2 as this is the game at present and probably for months to come

Cheers
Versus3k

[ZiRo]

Uhh, well Crossfire hasnt actually been publically released yet..

[Jah]

Nobody really knows for a fact which will be better, but initial benchmarks of Crossfire engineering samples look to have slightly better performance than an equivalent Nvidia setup. One thing to bear in mind is that ATi cards generally perform better than Nvidia cards at Direct3d games (BF2, HL2, etc etc) while Nvidia are generally quicker for OpenGL games (Doom3, CoD, Farcry), so it depends on what you'll be playing most really.

Also with dual cards I have to assume that you will be using AA & AF and historically ATi cards take less of a performance hit when running with AA/AF on... Dunno about 7800 GTx though as there is no equivalent ATi card to compare it to yet.

Personally I think either would be fine and the differences would not be huge.

BTW the DFi crossfire board is slated for release by the end of the month, good luck with your purchase :)

[-TSF-Gen. Romano]

well i think crossfire will be better because you dont need the same card

[lcplsickoll]

Crossfire isn't out yet, but should be really soon. Crossfire will be compatible with all games unlike SLI. Crossfire also requires you to buy only a support card at a cheaper price than buying 2 Nvidia cards. For example and X850XT PE for around 500 w/ 300 crossfire card 800 total or 2 6800 Ultras for around 500 ea 1000 total and you can upgrade your ati card without having to buy a new crossfire card. 1 crossfire card for all X850s and there's 1 crossfire card for X800-X800XT. With SLI if you go from a 6800GT to an Ultra you have to purchase 2 Ultras....$$$ I can't confirm the Crossfire card prices, I could've sworn I saw them yesterday, but I can't find them now. Regardless it's cheaper to buy one card during an upgrade than 2.

[GlobalFear]

Whats the point in comparing a product that hasn't been released yet?
Reminds me of all of those people that make polls about what next gen console is the best.

[lcplsickoll]

The point is that it's a product that is going to be out very very shortly, and this person is wondering if he/she should go SLI now or wait for Crossfire.

[Bramski420]

I'm building a new gaming machine too and I'm waiting until crossfire and the new R520 GPU from ATI hits the shelves. Reasons being, I don't want to build a new system around the SLI 7800gtx only to find ATI's latest offering in crossfire wipes the floor with Nvidia. I'm not saying it surely will because nobody will know for certain until the 2 go head to head in benchmarks.

Another reason is the price factor, at the moment an SLI mobo and 2 7800gtx's will set you back around £720, fast forward a month or 2 and you can knock maybe £50-70 off that price, maybe more depending on what the R520 is going for.

I guess when you're spending some serious cash for a setup that will be your pride and joy over the next 12-18 months you don't want to end up blowing your wad only to find you could have gotten something so much better if you had only just waited a little bit longer.


Alternatively, You could always just buy whatever the hell you wanted and just Ebay it once the next new thing comes along.

[lcplsickoll]

Alternatively, You could always just buy whatever the hell you wanted and just Ebay it once the next new thing comes along.

Story of my life. I upgrade this damn machine every 3 months easy

[imported_CoWBoY]

http://www.anandtech.com/video/showdoc.aspx?i=2477

It wipes something for sure, I wouldn't exactly say the floor though. :laugh: It has taken nVidia a bit to get chipsets right. We've had nForce, nForce 2, nForce 3 and now nForce 4.

TBH, I would wait for at least a second version of Crossfire before jumping into it. :)

[jdogg88-Fed]

Whats the point in comparing a product that hasn't been released yet?
Reminds me of all of those people that make polls about what next gen console is the best.

lol yeah y even do that cant say which one is better cause nobody has tried it

[NoSoup4You]

Performance wise, Crossfire will be much better. It is also a lot more flexible, however it comes at a price (a quite expensive price).

However, SLi is already on the market and is cheaper to complete. However it is a lot more fickle and requires special drivers.

[Versus3k]

Thanks for the feedback guys, much appreciated. I know it is a little silly to ask which is better of the two technologies seeing as Crossfire isn't actually out yet but what I was trying to gage was whether to get SLI now or wait for Crossfire (just as lcplsickoll said).

Looking at the benchmarks from AnandTech that CoWBoY posted, it appears the 7800 owns at the moment. One thing NVIDIA has over ATI is Shader Model 3 which is not supported by current ATI cards. I have no real idea what SM3 is but it sounds good lol. I wonder if the R520 will support it?

[ahho]

well you can said that nvidia need two identical card when crossfire isn't even out. once competition is out, nvidia would do the job

[Jah]

I wonder if the R520 will support it?

Sure will. :)