SLI v. Crossfire

[DaGaffer]

What's all that about then? If I get a PC with an SLI mobo am I stuck with nVidia cards, and ATI with Crossfire? Or is it even more complicated than that? Should I be making SLI or Crossfire one of my new PC criteria in the first place?

 

[TdC]

heya Gaffer. um, for extending the expected lifetime of your kit, performance wise, I would get an SLI mobo with *one* of your intended gfx cards. by the time your card of choice is devalued enough to be worth getting again it would well be worth the investment to crank up some of that treasured performance.

do be aware, you *won't* be getting a 100% or even a 50% gain, but you may be able to jump up a notch, resolution wise, etc. I say nVidia, because those are the only ones I've ever had in SLI mode. Also, I advise against getting an exotic card like the GX2 models (two GPU's on one card). I've had one and they are pretty fiddley tbh; two single cards work better.

Finally, when creating my current system I didn't go for SLI because I didn't think it would be worth it.

 

[Jonty]

Hi DaGaffer

You're right that SLI is nVidia technology and Crossfire is ATI/AMD technology, therefore they are not interoperable (although they both do the same thing). Some of Intel's chipsets support Crossfire, so if you want SLI you'll need an nVidia chipset motherboard.

Personally I wouldn't make it a high priority for your new motherboard. SLI/Crossfire is good, but it's still not perfect (some games aren't supported, crashes and glitches can occur, and performance improvements aren't always as good as you would hope). It's true that things are becoming better, but SLI/Crossfire is ultimately a fairly niche technology. It's generally true that one enthusiast card (e.g. 9800 GTX) will outperform two mainstream cards (e.g. 9600 GT).

As for which system is better, SLI has been around longer and has a variety of different configuration options available (e.g. improving image quality or performance or physics, using different cards together, even combining integrated GPUs and standalone GPUs in some cases). That said, Crossfire is no slouch and it certainly holds its own (and in some instances betters SLI). You should also consider the cards themselves, as nVidia has been on somewhat of a role lately, whereas AMD's performance has been good, but far from stellar.

So in short: the two technologies are not compatible; I personally wouldn't make it a priority, but if push came to shove, I'd chose nVidia's SLI because of their cards and pedigree.

Kind regards

Jonty

Edit ~ Having just read TdC's post, I agree, especially the part about not buying two graphics cards straight away.

 

[DaGaffer]

Thanks guys, I didn't intend getting two cards now, but while I'm still humming and ha-ing about getting a new PC, I figure I want one with as many upgrade possibilities as I can manage. This came up because I was using a website yesterday that had a PC-configurator-thingy and I noticed it had put an nVidia card with a Crossfire board and it rang alarm bells!

 

[SawTooTH]

I think you need to factor in the resolution you will be running games at before you go down the Sli route.

I have a large monitor and can run games at fairly high resolution with my Sli set up and they look better but whether its actually worth the investment is a good question to ask. Games can be particularly flakey though the standard FPS s generally run without too many problems.