NVIDIA Announces GeForce GTX 480M Mobile GPU

[Caparroz]

I've heard they were working on 512, but I don't know why they ended up with 480. Maybe they got in trouble with power usage, heat, yield, etc., or all those lies from that genius with claims about insider info, or all those great Charlie-histories. But maybe not, who knows? Are you claiming to know?
But the reality says they didn't (and still doesn't) need 512 to beat the 5870. Maybe they discovered it at the end and that's why they settled with 480. The GTX 480 has manged to perform with good enough margin above the competing GPU (5870) and that's all that matters in this business, the rest is history. I hope this logic can blow up the little that was left, if any.

Fermi design was set in stone before all those troubles (yield problems, leaking, thermal performance, TSMC, etc.) arised. Nvidia had a good idea how it would turn out but it's impossible to be 100% sure until you have actual silicon in your hands. But they couldn't go back to the drawing boards once they realised they're in trouble, this takes years. There's a thing called time to market.

Fermi was supposed to have 512 working cuda cores, it's not like Nvidia said, "Uhm, OK, 480 cores is just fine". All those problems combined resulted in this "catastrophic" failure (like an air plane crash) and Nvidia had to do a lot of adjustments to release the gf100 as we know it now.