Power In SLI/CrossFire And Watts Per Frame
One chart that was missing from the Radeon HD 6990 story, and subsequently requested, was a power consumption chart comparing the dual-Cayman board to CrossFire’d and SLI’d configurations. “Fair enough,” I thought. “We’re telling folks to skip the 6990 entirely and buy 6970s or GTX 570s—it’s reasonable to want to know how those setups size up with regards to power use.” So, here’s that graph:
In addition to the 6990, 6970s, and 570s, I’ve also added the 590 and a pair of 580s in SLI.
Clearly, two GeForce GTX 580s ratchet up power use in a way that no other setup comes close to rivaling. The other solutions are much more evenly matched, though.
| Header Cell - Column 0 | Average Power Consumption (Metro 2033, Three Runs) |
|---|---|
| Nvidia GeForce GTX 590 | 437.27 W |
| Nvidia GeForce GTX 580 SLI | 559.85 W |
| Nvidia GeForce GTX 570 SLI | 420.35 W |
| AMD Radeon HD 6990 | 402.30 W |
| AMD Radeon HD 6970 CrossFire | 442.18 W |
On average, the GTX 580s impose a 559 W system power figure running Metro 2033. Two Radeon HD 6970s in CrossFire are the next most power-hungry, averaging 442 W system power. The GeForce GTX 590-based system is just five watts behind, while two GTX 570s turn in an average power figure of 420 W. AMD’s Radeon HD 6990 (running at its stock clocks) winds up being the most power-friendly option, registering 402 W average system power.
Here’s the average frame rate each configuration achieved while we logged those power numbers.
A couple of folks looking to deflect criticism of the 6990’s value asked for a chart depicting watts per frame. There you go, gentlemen. The Radeon HD 6990 uses less power per frame per second than two Radeon HD 6970s, and both AMD-based configurations consume less system power per frame than all three Nvidia-based setups. Now, flip back to the previous page, replay the 6990 video, and think about all of the conversations you can enjoy not hearing!
