Have a question for you PC gurus...what's the advantages/disadvantages of running a ATI Crossfire setup compared to a ATI single card?

I've tried HD5830 + HD5830, HD5830 + HD5870, and HD5870 + HD5870 -- in 3 monitor Eyefinity and single-monitor. Just recently switched to single HD7970 for Eyefinity and single-monitor.

The advantage: More FPS. Depending on the game or benchmark, FPS increased 75 percent to over 95 percent -- when Crossfire worked.

CrossFire works on most games. Most games are GPU (graphics card) limited -- that is, more graphics power means more FPS.

Often, for single monitor games, Crossfire is overkill. Most single LCD monitors only refresh at 60FPS maximum. So, getting 90FPS or 120FPS means nothing -- you only see 60FPS on the screen. Most single graphics cards can deliver high enough FPS for a single 1920x1200 monitor. Exception, there are some 30 inch monitors with lots of pixels -- they need CrossFire or a single HD7970.

With 3 monitors, there are a lot of pixels to fill. CrossFire makes 3 monitor gaming feasible with most any game. However, the latest HD7970 card is equal to crossfired HD5870 and nearly equal to crossfired HD6970 -- so a single HD7970 will handle 3 monitors.

Some games are very CPU limited. That is, one gets pretty much the same FPS with one card or two -- because its not the graphics card holding things up. In such games, CrossFire (or SLI) don't much, if anything. Skyrim and the original IL-2 are like that.

In some games, CrossFire or SLI is not properly supported and cannot be used without problems. The AMD/ATI drivers recognize those games and "turn off" Crossfire for those games.


All in all, I recommend CrossFire if one already owns a fast AMD HD5xxx or HD6xxx card (but not the latest HD7950 or HD7970) -- it can be a cheap upgrade to buy the second card on super sale.

If one is looking for an all new graphics card setup, then, I recommend HD7950 or HD7970 -- they can do it all without needing Crossfire.

Lastly, if buying new: HD7970 and GTX670 and GTX680 are competitive on "Single monitors". With triple monitor or in "compute" applications, the HD79xx has the clear lead.

Just my opinions

Thanks for the imput, Allen....I really don't know all that much about Crossfire and can use all the help I can get.

I'm running a HD 5850 that gives me good frame rates overall in everything I run with pretty high settings, was just looking to get a little more if possible. I was looking at some of the latest benchmarks and my old card performed right with the majority of the ones I was looking at. I can't see spending $250+ bucks for a few FPS only. I can get an identical card to mine at a very good price, so I thought I might try that as an alternative until I decide to spend $4-500 on a new video card.

One thing that concerns me is my MB will lower the PCI-e lanes/channels/whatever they're called from x16 to x8 in a Crossfire configuration. Makes me wonder if having double the video processing power is worth losing half the ability to provide GPU output.

Gonna have to do some more reading on that and Crossfire.

If you can get that second HD5850 for a real good price, its a good way to go.

Initially, I had an HD5830. I decided an extra HD5830 in CrossFire would beat most top end cards at a lot less $$$. It did You have an HD5850 -- a second one will give some real good performance in the GPU dependent games -- beating all but the fastest single cards (the one's selling for close to $400 and up).

The 16x vs 8x thing is NO problem. Won't make any difference because the cards don't nearly use the bandwidth -- even 4x is enough.

Only real issue -- get the HD5850 at a price you consider cheap. You could also use an HD5870 -- however, coupled with an HD5850 the two cards would run like two HD5850.

You might consider it a low cost fun experiment, I did. Kind of fun to beat the expensive cards with such a cheap upgrade

Based on my experience trying to game using two AMD MSI Lightning 6970s in crossfire, I would suggest avoiding it. Like the plague.
The ratio of gaming to troubleshooting was about 1:1. Lockups, DX diagnostic errors, game crashes (mostly BF3, ME3, Skyrim). I posted it about in some detail here a few months back. And temperature issues. Overall, the experience sucked, and I will never again go dual cards, be it AMD or NVIDIA. You're just tempting Murphy's Law when you add a 2nd card to the mix. Then again, I am not a savvy tech person with with a water cooled rig and lots of ability to troubleshoot and fix things. I recently got so fed up with it that I sold both 6970 cards so I wouldn't be tempted to waste more time troubleshooting. But regardless, if you just want to game and enjoy, go single card. And the high end cards of today are powerful enough to run any game you care to play, assuming youre not gaming at resolutions over 5780x1200 or so. To say nothing of the fact that AMD's driver support (especially for Crossfire) is sometime less than prompt, even for AAA games. Maybe NVIDIA has the same problem(s), I dunno. Just my .02. Your experience may vary, but it would definitely behoove you to research the drawbacks.

FWIW, I had very few issues with CrossFire. Most games worked -- that I play. However, I never expected it to work all the time.

Never stopped me from playing a game with a single card active -- normally with very good FPS. That's the nature of the games. The ones that can't use CrossFire or SLI well are usually CPU limited and work fine with any old single card. Use CCC to make a couple presets -- one for single card and one for CrossFire.

That's the thing, both CrossFire and SLI have issues with some games -- so you have to turn off one of the cards and play with a single GPU for those games -- or you may have unending problems with a particular game.

If money is no object get a single HD7970 (for 3 monitors or single monitor) or single GTX670 (if you are using a single monitor). Otherwise, a cheap second HD5850 seems worth a try, to me (having owned dual HD5830 and dual HD5870 as noted above).

Just my opinion. We all give our opinions and let the "question asker" sort it out. No rights or wrongs on this friendly site (as you have probably noted over the years)

I've seen both opinions from my reading of Crossfire....both the pros and cons. It's kind of like PC's themselves I guess...some people's run great all the time and some people are always having problems.

There's some games that aren't Crossfire capable yet, including one of my favorites when I'm not pissed off about it's development...LOL...and have a lot of problems with it. From what I've read, the majority of those are multi-screen users and it's been with both ATI and nVidia users it seems.

I'm only running 1920, so I might not even see much of an advantage with a Crossfire setup...but, I also might see a very big one, too. Guess I'll find out and if it doesn't work to my liking, I can always take it out and go back to the single configuration. If nothing else, it'll be a learning experience and I might invent some new "choice" words while dealing with Crossfire.

Allen makes a good point re: just disabling Crossfire if it doesn't work for a game. For me, it didn't work properly with nearly every game I wanted to play, which made it kind of pointless.

Allen, do you have any useful links/reading about Crossfire handy?

My experience with Crossfired 5870s was that it was beneficial on the particular games that supported it and on the games that it was not supported or problematic Crossfire could be disabled, which became even easier with the AMD drivers that allow for app profiles to do that easily, so Crossfire is ok as long as you don't expect it to be something beneficial to *all* the games, and you can usually google the games you play the most and find out if it is supported or not.

Also Allen I'm not sure where some of the data you are seeing about the 670 not comparing well for 3 monitor to the 7970, I have one which is working great for all the triple monitor games I have tried so far, so I can only think maybe it is because you are comparing the top single GPU AMD 7970 to the baby brother Nvidia single GPU 670 and you maybe mean the 680? I'm guessing the performance will be off by <10% or something?

As a very non-biased AMD/Nvidia fan who switches camps all the time, so far my 670 has made me very happy for triple monitor bang for the buck, so I'd be interested to hear what is giving you the opinion it's not matching up to the 7950 for triple monitor which is the true AMD comparison, not the 7970?

BTW back to the OP, having done Crossfired 5870s and been underwhelmed at the number of games *I play* that benefited it, I would still be willing to Crossfire or SLI again as long as the second card was cheap enough and the single card model was fast enough to handle the games that didn't benefit from the second card, there will likely be a SLI 670 in my future once the cards hit the $200 price point.