Power consumption
We measured total system power consumption at the wall socket using a watt meter. The monitor was plugged into a separate outlet, so its power draw was not part of our measurement. The idle measurements were taken at the Windows desktop, and cards were tested under load running Half-Life 2: Lost coast at 1600x1200 resolution with 16X anisotropic filtering and HDR lighting enabled.

There's good news and bad news here, I suppose. The bad news is that the GeForce 7800 GTX 512 requires an awful lot of power—nearly 30W more than the Radeon X1800 XT when running our test scene. The good news is that NVIDIA's aggressive clock throttling when no 3D applications are running translates into reasonably low power consumption at idle.

Throw two of these monsters together in SLI, though, and watch that electricity meter spin!

Normally, I'd also take a noise level reading off of the cards, but a gimpy chipset fan on our A8N-SLI Deluxe motherboard made me abandon that cause. The numbers that I was getting were, to use a highly technical term, utter crap. The chipset fan sometimes rattled and threw everything off.

Instead, I can tell you using my own two ears that the massive fan on the GeForce 7800 GTX 512 does its job pretty well without creating any B-52-like aural performances. At idle, it's nearly silent, and under load, it doesn't tend to spin fast enough to make much noise. I'd rate is as quieter overall than the Radeon X1800 XT.

I do have a nifty new Asus A8N32-SLI motherboard here in Damage Labs now with a passive chipset cooling config. We'll do sound level testing with that motherboard next time around.

Overclocking
I didn't get fancy when attempting to overclock this thing. I just used NVIDIA's "Detect optimal frequencies" button in the graphics control panel, and the speeds came back as 604MHz for the GPU core and 1.8GHz for the memory—right at Samsung's rated speed for those GDDR3 chips.

The higher core and memory clocks allow us to squeeze out a few more frames per second. Phew.