ATI Radeon HD 4850 Preview: AMD Delivers Performance for the Masses

Assassin's Creed

Two GeForce 8800 GTs in SLI outperform a single GeForce GTX 280, and two Radeon HD 4850s in CrossFire outperform the 8800 GT SLI, so AMD manages to outperform NVIDIA's brand new GT200 with a pair of cheaper, slower cards. The two actually end up performing like a GeForce 9800 GX2 here as well.

It's not so much that the Radeon HD 4850 is ultra competitive, but rather that the GTX 280 isn't terribly competitive with NVIDIA's own $400-$500 multi-GPU solutions.

Assassin's Creed has a ~60 fps frame rate cap, so the flat performance of the 4850 in CrossFire simply indicates that it kept bumping off of the frame rate limiter resulting in static performance throughout all three resolutions.

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Oblivion

While CrossFire tends to not scale as consistently as SLI, when it does, it scales very well. The performance of two 4850s is nearly double that of a single card and it puts AMD at the absolute top of the performance charts here.

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The Witcher

The Witcher is a good example of an area where CrossFire fails to scale - despite the Radeon HD 3870 X2 scaling, we could not get the 4850 to show any performance benefit with two GPUs. It could be an issue with the 4850 drivers or a special trait of the 3870's driver, at this point it's tough to tell.

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Bioshock

While we see scaling at 1920 x 1200, at 2560 x 1600 there's no benefit to two 4850s over one. We could be bumping into a memory bandwidth limitation or some continued strangeness in AMD's CrossFire drivers.

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