HD 2900XT Crossfire vs. HD 4850

[ghost recon88]

I can get a pair of HD 2900XT for relatively cheap, cheaper then a single HD 4850. I know the HD 4850 is a lot newer, but would the HD 2900XT in Crossfire be better for gaming then a single HD 4850?

 

[AstroManLuca]

According to this chart, it's pretty much a wash. The 2900XTs seem to do better in Mass Effect, World in Conflict, and 3dmark, while the 4850 is better for COD4, HL2, and Quake Wars.

I guess it comes down to price and whether you have a robust enough PSU to handle two 2900XTs. How cheap can you get them? Because another popular option seems to be to use 4830s in CF, which ought to do better than either of your proposed configurations and they draw less power to boot.

 

[MarcVenice]

Hmmm, the 2900xt isn't slow by any means, it performs like a 8800gts 640mb, which is a roughly equal to a HD3850. Two of them would probably be equal to and/or faster then a HD4850. Then again, 2 of them in crossfire will eat a lot of juice.

 

[alcoholbob]

long term cost of 4850 is less...unless your parents are footing the power bill, in which case go for what's cheaper for yourself, lol.

 

[SlowSpyder]

Originally posted by: MarcVenice
Hmmm, the 2900xt isn't slow by any means, it performs like a 8800gts 640mb, which is a roughly equal to a HD3850. Two of them would probably be equal to and/or faster then a HD4850. Then again, 2 of them in crossfire will eat a lot of juice.

2900XT should be much closer to the 3870 in speed as it has a 745MHz core (vs. 600MHz for the 3850 and 775MHz for the 3870). The 2900 also has a lot more memory bandwidth then either the 3850/3870.

But, I would think even if the 2900XT scaled perfectly, 100% it's still add up to less then the 4850 specs (640SP vs. 800SP, less texture units) but with higher clock speed and more memory bandwidth. I would think the 4850 would be a more balanced card and use less power while gaming, so I'd go with the 4850.