What I don't understand is why people are so concerned about power usage/heat with cards of this calibre. Surely you know these cards aren't going to run eco-friendly before buying it? Anyone care to shed some light on this, or am I wrong?
No one does care about power.
If one card uses 150W and another card uses 450W, but is 3 times faster, who cares.
If one card uses 180W and costs £300, and another card uses 300W, is £450, and only offers 10% more performance, the power/heat/noise/price just become unacceptable FOR THE LEVEL OF PERFORMANCE OFFERED.
if the £400+ 480gtx on launch offered 30-50% more performance, I'd have got one, it would have offered good value and the power was being used for something I could see, feel and be worthwhile.
When it offered no real perceptible difference power/heat were just the last on a long line of reasons in the "con" column when deciding if you should buy.
Think of it more directly, if there was a 180W 5870 and a 250W 5870 that offered a 5% overclock but took a huge amount of power to do so, that heat and power translates into higher noise, harder to cool, is it worth the 5%, no.
Heat and power aren't the "only" reasons Fermi was a poor choice last gen, it was the 5th and 6th reason, not really important but still a factor.
As for power, its worth noting idle if you have two screens is significantly higher power/speed draw on the 480gtx, I'm not entirely sure how that stacks up with the 580gtx, its not a huge deal, this whole screens flickering and increased clocks needed for dual screens is some utterly retarded thing both Nvidia and AMD got wrong, or maybe its another rule/standard/spec/os/driver thing they were forced into, I really don't know.
Its retarded that a 150Mhz gpu can deal with one screen, while never having a 1% load on the gpu, but it can't deal with 2 screens also with essentially no load so has to jump up.
Dear god I hope AMD/Nvidia sort that out for the next gen as its one of the single most retarded things they got wrong, more so seeing as they both pushed this gen of cards as "surround gaming" generation so expecting more than one screen.