CrossFire - Explain it to This noob.

[kyosuke]

Ok, So when I built my new PC earlier this year, I built it with the understanding that by the end of the year I would utilize the CrossFire in the system by having two graphics cards.

In the past (SLI world) I always thought the graphics card had to be identical? But I understand these days that is not the case?

I have a Sapphire Radeon HD6870 1GB in my system now, so do I need another HD 6870 to match up with it? Same brand/model? Or can I use an HD6970 for example different brand, etc...

I'm a noob when it comes to multiple GPUs, so any ideas/advice on this would be great!

Thanks much!!

 

[anarxi]

http://sites.amd.com/PublishingImages/Public/Graphic_Illustrations/WebBannerJPEG/AMD_CrossfireX_Chart_1618W.jpg

Different brands work together.

Ok, So when I built my new PC earlier this year, I built it with the understanding that by the end of the year I would utilize the CrossFire in the system by having two graphics cards.

In the past (SLI world) I always thought the graphics card had to be identical? But I understand these days that is not the case?

I have a Sapphire Radeon HD6870 1GB in my system now, so do I need another HD 6870 to match up with it? Same brand/model? Or can I use an HD6970 for example different brand, etc...

I'm a noob when it comes to multiple GPUs, so any ideas/advice on this would be great!

Thanks much!!

 

[Wolfshadw]

What the image anarxi linked to says is that you can pair your current HD6870 with either another HD6870 or with an HD6850. It does not need to be of the same brand.

-Wolf sends

 

[ilysaml]

Crossfiring Multiple GPUs must be within the same series, you can't CF HD 6970 with HD 6870, but you can CF HD 6870 with HD 6850.
Crossfire generally improve the performance over a single GPU by 20-40% depending on the GPU.

Crossfiring HD 6870 is not a good idea, HD 68xx series are known of Microstuttering, a common issue appears with low end GPUs when you go 2-way CF.

So i suggest that you sell the HD 6870 and get something like the HD 6970 or better wait for the new HD 7K series... they will be released December 6.

 

[jyjjy]

You can crossfire an HD6870 with an HD6850 or HD6790 as they use the same GPU but mixed crossfire is generally not a good idea.

 

[billj214]

I don't recommend Crossfire or SLI!

Excessive heat generated, larger case required.
Large power supply required, 750w +
Some games don't work well with Xfire or SLI due to drivers.

Sell your card, put the money towards an upgraded card, you also save money from buying a new power supply and case!

 

[vitornob]

I do have a SLi system.
And what @billj214 told is true.

Sli and Crossfire is good for a two-step cheap upgrade, buying one VGA, and after some time buying the other one.
If I could I would buy a single card, but since going Sli was a cheap and fast way to almost double my fps output, I went this way

 

[toxin440]

Crossfiring Multiple GPUs must be within the same series, you can't CF HD 6970 with HD 6870, but you can CF HD 6870 with HD 6850.
Crossfire generally improve the performance over a single GPU by 20-40% depending on the GPU.

Crossfiring HD 6870 is not a good idea, HD 68xx series are known of Microstuttering, a common issue appears with low end GPUs when you go 2-way CF.

So i suggest that you sell the HD 6870 and get something like the HD 6970 or better wait for the new HD 7K series... they will be released December 6.

Source for your december 6th prediction?

I was super excited about the 7000 series and was going to wait but even AMD themselves a few weeks ago said that a end year launch was looking less and less likely. I picked up 6950 2GB for a good price from the egg.

Even if they DID launch it, it would be a paper launch and the odds of you finding an actual card to pickup anywhere is pretty much none. If AMD can pull some magic (and they do need some magic after bulldozer) with a perfectly priced 7950 I would consider upgrading... odds are good though I'll keep my current GPU and perhaps crossfire it though.

 

[ilysaml]

Source for your december 6th prediction?

http://www.tomshardware.com/news/amd-southern-islands-28nm-gpu-ati,13715.html
As i expect, they will push the HD 78xx late on December, and delay the high end XDR2 in Q1 2012 to compete with nVidia's

 

[bystander]

Crossfiring Multiple GPUs must be within the same series, you can't CF HD 6970 with HD 6870, but you can CF HD 6870 with HD 6850.
Crossfire generally improve the performance over a single GPU by 20-40% depending on the GPU.

Crossfiring HD 6870 is not a good idea, HD 68xx series are known of Microstuttering, a common issue appears with low end GPUs when you go 2-way CF.

So i suggest that you sell the HD 6870 and get something like the HD 6970 or better wait for the new HD 7K series... they will be released December 6.

Mostly agree, but the crossfire improvement on performance is much higher than that on average, it's closer to 60-70% by all the benchmarks, but of course their are games which will only see 20-40%, but others see 100% improvement as well.

 

[ilysaml]

Mostly agree, but the crossfire improvement on performance is much higher than that on average, it's closer to 60-70% by all the benchmarks, but of course their are games which will only see 20-40%, but others see 100% improvement as well.

hmm.. i agree with you it could be above 40%, but i never saw the double the performance of a CF or SLI that makes you say 100%, definitely i would CF my HD 6950 tomorrow if it gives the double the performance.

 

[beenthere]

Crossfire and SLI are a means to remove a lot of dollars from your pocket and place them in someone else's pocket.