How to overclock Radeon HD 2900 XT CrossFire

[Andreas G]

For the last few months we've been doing quite a lot of benchmarking and testing with the Radeon HD 2900 XT. Overclocking a single graphics card has proven to be quite a challenge, and overclocking two of them in CrossFire mode is even harder. Especially as the drivers don't bring support for overclocking cards running CrossFire, but ATI decided to find a workaround for the most extreme users by supplying BIOSes with adjusted frequencies. These are not for everyone though. But today we can present you with this guide that shows you how to overclock Radeon HD 2900 XT CrossFire. No need for any additional BIOSes, just a few simple applications available for everyone.

"We've received many e-mails över the last few months regarding how to overclock two Radeon HD 2900 XT in CrossFire mode. Unfortunately we haven't had a good answer for you, but with some help from macci, now a resident of AMD/ATI, we can now present this guide, which shows you how to overclock Radeon HD 2900 XT when you have two of them running in CrossFire mode."

:: How to overclock Radeon HD 2900 XT CrossFire

[Mean Machine]

Now all I need is a guide to make it work on my NF7.
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Grandis spiritus, sanctus diavolos

[Delph1]

Macci and ATI have been of great assistance during the making of this article! Hopefully it won't be needed for long though

//Andreas
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"I'm sort of a postmodern vegetarian, I eat meat ironically"
"You are our Swedish superhero "

Forget everything, knowledge is your enemy, it's only going to make you second-guess yourself."

[miamimuscleboy]

Can you guys tell me if you tried this in vista I use the gpu tool with the modified tool.dll file but the problem is before that . when i try to switch displays and check the extend and hit apply the check mark comes back off and i cant enable the 3rd display which is the one for the second card it just keeps staying on the first primary, so I cant overclock the second card if i try it locks up because i cant do the switching of the display, and idea why , all i get is that message saying your current display driver does not allow hardware accleration changes as well, im on vista 32 and cat 7.9 and the new hotfix
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E6750 @3.5 , msi p35 neo2 FR 16x/4x 2 hd2900xt crossfire silverstone 750 strider 4gb ddr2 1068 , vista 32 proof that crossfire does work in 3dmark06 but forget about most dx10games its horrible ! Found out how to overclock 2nd card in VISTA Xfire with atitool ! will post 3dmark6 scores regular CF and CF overclock 1000 to 1200 point diffrence when ocing 2nd card

[Delph1]

Haven't tried it with Vista yet. Try connecting a DVI-HDMI adapter to the second card before switching monitors in the Desktop control panel.

You might be able to fool Vista that way.

//Andreas
_________________
"I'm sort of a postmodern vegetarian, I eat meat ironically"
"You are our Swedish superhero "

Forget everything, knowledge is your enemy, it's only going to make you second-guess yourself."

[miamimuscleboy]

tried it even attaching a real monitor ??? doesent work either . is the only solution getting the real 8pin pcie on both cards??? my psu dosent have them but the 6 to 8 pin pcie connectors i bought dont fit the 8 pin card slot , i think someone was just out to make money on those, got it from frozen cpu ????
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E6750 @3.5 , msi p35 neo2 FR 16x/4x 2 hd2900xt crossfire silverstone 750 strider 4gb ddr2 1068 , vista 32 proof that crossfire does work in 3dmark06 but forget about most dx10games its horrible ! Found out how to overclock 2nd card in VISTA Xfire with atitool ! will post 3dmark6 scores regular CF and CF overclock 1000 to 1200 point diffrence when ocing 2nd card

[Delph1]

You don't need the 8-pin, just two 6-pin for each card. The 8-pin is mainly for reducing load so to speak, you can still overclock the cards just fine with two 6-pin connectors.

I'll see if we can't find a work around for this.

//Andreas
_________________
"I'm sort of a postmodern vegetarian, I eat meat ironically"
"You are our Swedish superhero "

Forget everything, knowledge is your enemy, it's only going to make you second-guess yourself."