You do realise that 450 watts is for the entire system and not just the card right? benchmarks are decieving
They should do power tests with no/integrated GPU to determine base power usage. Then add the card and see what the idle/load draw goes up to and then you can calculate what the draw for the actual card is. For example, let's take this graph:
And take 450 (load consumption of entire system with the 480) and take away 280 (load consumption of system with the 5850) and then you get a basic idea of the draw of the card. in this case it's 170 watts for the card alone. So then, you take 450 + (3 x 170 ) and it =
960 watts draw with 4x GTX 480's
Let's use the same calculation for idle usage.
146 - 114 = 32 so 146 + (3 x 32) =
242 watts idle draw for 4x GTX 480's
If the GTX 4xx series drew over 300 watts they would not be allowed to sell them due to some regulation or something. it has something to do with the PCI-E spec i believe. not sure.
Just thought i'd get that off my chest lol.
and the calculations aren't accurate because we don't know the usage of the system without a GPU or using an integrated (if any.)