We measured total system power consumption at the wall socket using an Extech power analyzer model 380803. The monitor was plugged into a separate outlet, so its power draw was not part of our measurement. The cards were plugged into a motherboard on an open test bench.
The idle measurements were taken at the Windows Vista desktop with the Aero theme enabled. The cards were tested under load running Half-Life 2 Episode Two at 2560x1600 resolution, using the same settings we did for performance testing.
We didn't test idle power use for the 4870 X2 in our preview because AMD didn't have all of its PowerPlay mojo working correctly yet. Now it can be told, and the story isn't too bad, considering. The 4870 X2 system only draws 20W more at idle than the same system equipped with single 4870.
When running Episode Two, the 4870 X2-based system draws a little more power than a comparable two-way GeForce GTX 260 SLI rig. And with dual 4870 X2s in the system, we do indeed have what is, I believe, a new power-draw wattage record for one of our test rigs. To its credit, our 750W PC Power & Cooling PSU didn't explode during this test. In fact, I tested power consumption last and had no idea how close to the edge the PSU must have been throughout our performance testing.
Per your requests, I've added GPU temperature readings to our results. I captured these using AMD's Catalyst Control Center and Nvidia's nTune Monitor, so we're basically relying on the cards to report their temperatures properly. In the case of multi-GPU configs, I only got one number out of CCC. I used the highest of the numbers from the Nvidia monitoring app. These temperatures were recorded while running the "rthdribl" demo in a window. Windowed apps only seem to use one GPU, so it's possible the dual-GPU cards could get hotter with both GPUs in action. Hard to get a temperature reading if you can't see the monitoring app, though.
Our production 4870 X2 cards run a little bit cooler than the pre-production sample we tested, thank goodness. I'd like to have noise level results to present alongside these temperatures, but unfortunately, I just ran out of time to test it all. I may try to add those results in the next day or two, so you might check back here later.