crossfire pairing

[graphics whore]

I currently have a sapphire 5870 1gb and am looking to get something to corssfire it with. No reason, just love wasting money it seems!

If i got a 5970 2gb would it all work perfect if i match all the clock speeds?
Does it have to be the same brand or can i mix and match?
Whats the difference between brands/models?

not realy looking to overclock them outside of what the warranty allows. seems to me the only difference between brands is the cooling system and maybee a tiny stock overclock

 

[Alex74]

In theory, afaik you'd have 3 card's worth of power, and all of them would be synchronised at the 5970 clock speeds. If you OC'd the 5970 to 5870 speeds (i think it's that way round iirc), then you'd have a lovely trifire setup (really though, just at stock the trifire performance would be epic ).

Also you can mix and match them no problem. There's some problems with some mixes but with those two you'll be fine. Quite a few people on the forums have that setup iirc so they should be able to answer any questions you have



oh and welcome to the forums!

 

[Daaaveee]

Any 5000 series cards will Crossfire with each other, however they will all run at the clock speeds of the lowest one.

A 5970 would work fine with a 5870 and give you a TriFire setup, however the 5870 would downclock as the 5970 is more like a pair of 5850s sandwiched in to one card.

Most people running TriFire with a 5970 + another card use a 5850 because of this (cheaper way to do it), however seeing as you aready have the 5870 its no problem but you will just lose out on the extra the 5870 is capable of

 

[Phoenixdancer]

simple fix for above....

raise the 5970 to 5870 core speeds and you have 3x 5870 gpu's....

 

[Alexrose1uk]

Edit: Completely misread the OP. Sorry.
A 5970 should work fine with your 5870 in crossfire, just as mentioned the 5870 may be held back to 5850 levels unless you overclock (although in trifire that should still be bloody fast).

You can mix and match brands. You might also find it worth considering just getting another 5870, as from what I've heard, 2 card support is better (because its more common) than tri-fire, and performance will still be high. If you're happy and have a decent enough PSU though to go for the additional 5970, go for it

 

[graphics whore]

thanks guys, does anyone know how high a 5970 will clock?

 

[Alexrose1uk]

Completely varies, just like standard cards. I wouldnt want to make any statement on it haha

 

[graphics whore]

i just meant how high does CCC let you.
wouldnt want to void the warranty on something that expencive!!

persoanlly i would never overclock something that would void the warranty. i mean when u spend like 1500 on your rig 1. There is no need and 2. I could never afford to replace my i7 cpu or gpu's.
(contraversial on this site i know!! ha)

 

[Phoenixdancer]

mine does 1000/1300 :/