I reckon they wont be that high on the 3080. 3090 will have the highest sliders. 500W I reckon.
I meant the 3090 specifically, but since the majority of boards are going to be identical between the 3080 and 3090 variants I would have thought they'd be capable of doing the same sort of power limits on both.
I'm just not sure if we're going to be able to flash custom BIOS's down the line when they eventually come out. NVIDIA seem to lock these cards down tighter and tighter every generation.