Crossfire different models / brands (HD 7970)

[Cloudie]

Hello everyone,

I've been looking at adding another HD 7970 to get some crossfire action going (Watercooled)! Now my concern is choosing which one to add to my current rig. Right now I have an early edition sapphire HD 7970 with a link provided below.

Current GPU (11197-06-40G):http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1157&lid=1&pid=1515&leg=0

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Loads of editions: http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1157&pid=0&psn=000101&lid=1&leg=0


Right now I'm having a hard time choosing which one to get. Normally I'd pick the exact same version, but I'm wondering about the improvements added in the newer versions and the cheaper prices of other brands...


1. Exact same model without the improvements of later revisions
2. Same brand / model but with the improvements (OpenGL4.1 vs 4.2 etc)
3. Any 7970 as cheap as possible (XFX HD7970 Double Dissipation (FX-797A-TDFC)) saving €70,-
4. Different brand with better specs

The idea would be to OC both of the cards to where it's possible. Does mixing different brand/version have an impact on preformance or is it recommended to get the latest revision possible?

 

[barkinos98]

well, there is no difference between the reference models, except brands. if you get a different design than reference model, you need to check to see if there is a waterblock for it. cheapest bet would be to check coolingconfigurator.*something* to see. all 7970 would work as long as it is 7970. the DD one had a revision change, and the board changed, so if you get one with 2 DVI ports, its the new one and no one makes full cover blocks for it. any card with 1 DVI port is based on the reference design, meaning it works with any standard 7970 waterblock.

hope this helps!

 

[Cloudie]

Alright.. cheers mate! So your idea would be go geat a cheap reference model for the second cpu (like the xfx)?
The sapphire does have a dual bios even though everything else seems exactly the same. Is there any difference in overclock potential on the xfx (like I see at some places) or just the exact same gpu with a different sign/cooler

 

[barkinos98]

no problem, and yes, getting a cheap reference gpu would be way easier on your side. about the overclock, its all up to your luck, some are golden but some are just impossible (not literally) to overclock. but, i see your card is reference too, so keep in mind that mostly any card with 1 DVI slot=reference models. XFX has 2 revisions of the same card, and the one with 2DVI has a different layout which creates problems, EK made a press release type of thing for that.

 

[seumasbeathan]

With crossfire it really doesn't matter what brand it is or anything, in fact you can even crossfire some different cards, but I would still go for the same card for one reason, it looks much better

 

[dugdiamond]

amd vs nvidia

nvidia in sli = they have to be the same card
amd in xfire = they can be different brands, but must have the same specs

(note: custom firmwares (bioses) can be flashed to some GPU cards to fix this issue)

 

[PittPyro]

amd vs nvidia

nvidia in sli = they have to be the same card
amd in xfire = they can be different brands, but must have the same specs

(note: custom firmwares (bioses) can be flashed to some GPU cards to fix this issue)

Wow thanks for the info Dug...I did not know that about nvidia cards. I always just thought that the cards just had to be the same chip and memory config....I was unaware that they also had to be the same manufacture.
Never came across that situation in any of the builds I have done as I always just used two of the same cards from the start. I never started with one and later upgraded.
Always nice to learn new things and useful too
Thanks