Benchmark Results: Dual-GPU Performance (CrossFire And SLI)
AMD’s Radeon HD 6990 is roughly equivalent to a slightly de-tuned pair of Radeon HD 6970s in CrossFire (both the default memory and core clocks are lower). It only makes sense, then, to compare the 6990 to 6970s in CrossFire. And while we’re at it, why not factor in a pair of GeForce GTX 570s as well?
Although AMD refused to confirm the price of its Radeon HD 6990 until just prior to launch (after our benchmarks were run and analysis completed), we do know you can buy a pair of Radeon HD 6970s for $680 or a pair of GeForce GTX 570s for $670. And that’s before rebates. Shave an extra $40 off the AMD cards or an extra $30 off the Nvidia boards if those count in your book. Keep that in mind as we go through the benchmarks.
Using the 3DMark Performance preset, two Radeon HD 6970s in CrossFire appear to be your fastest option. The Radeon HD 6990 with its shipping firmware setting actually takes last place. However, the overclocked BIOS facilitates a jump in performance that overtakes two GeForce GTX 570s.
Nvidia’s GeForce GTX 570s claim a first-place finish in Metro using AAA. Turning on 4x MSAA, however, hits the card’s frame buffer hard, and the pair of GF110-based boards actually drop to last place. The Radeons are much more consistent, though again we see the Radeon HD 6970s in CrossFire serving up slightly more speed than the Radeon HD 6990.
The situation plays out similarly in Lost Planet 2, and the GeForces outperform without AA, and then fall behind with the technology turned on. Again, the two 6970s edge out AMD’s new flagship card.
The field is close in AvP, but it’s differentiated just enough to show that the 6990’s overclocked BIOS gives the card parity with a pair of Radeon HD 6970s in CrossFire. This time, the GeForce cards bring up the rear with and without anti-aliasing.
We’ve seen this enough times for us to call it a pattern: the Radeon HD 6970s in CrossFire are the way to go.
AMD had so much trouble getting F1 2010 running in CrossFire using its latest driver that I skipped right over the results I compiled for that game and moved on to Just Cause 2.
The story is the same, anyway. Two Radeon HD 6970s are faster and quieter, making the 6990 a difficult sell.