When it comes to sucking down power the Diamond Radeon HD 4870 X2 does it with pride, as we see a total system consumption level of 462 watts under load, which is 10 watts less than two separate Radeon HD 4870 cards.
At idle the Diamond Radeon HD 4870 X2 was much more impressive, as the system consumption level dropped to just 202 watts. This is only 9 watts more than a single Radeon HD 4870 and 74 watts less than two separate Radeon HD 4870 graphics cards in Crossfire mode.
This is clearly an area where the GeForce GTX 280 shows some strength, even when the Radeon HD 4870 X2 is a dual GPU card, the GeForce has consumption levels that more closely resemble a standard Radeon HD 4870 card.
Like all new Radeon HD 4800 series graphics cards the Diamond Radeon HD 4870 X2 tends to generate a significant amount of heat when under the pump. Under full load the Diamond Radeon HD 4870 X2 reached 88 degrees, while at idle it never fell below 70 degrees.
We eagerly await for Radeon HD 4870 X2 cards that improve the stock cooling system, hopefully with little price penalty considering it's an already expensive piece of hardware.