so, what's the final verdict on the power draw of these 4830's? If they only consume slightly more than a 3870 with 640SPs enabled, that's great. Is that the case?
As far as I can tell this is still up in the air. It appears no one will be willing to settle this issue before Christmas.
With any luck we'll see a definitive answer to this sometime in 2009.
I think the power draw of these cards, particularly at idle, is going to vary wildly between manufacturers and I doubt many (any?) will match that of the reference card reviewed at SPCR. This has nothing (or very little) to do with disabled SPs though. I have yet to see any reference designs in retail, they are all redesigned to reduce cost and create a price differential from the 4850 (apart from the GPU itself, I can't see what's cheaper about the reference 4830 v the reference 4850). One obvious place to save cost is components involved with power and voltage regulation. Less effecient power handling is a likely result, along with less aggressive Powerplay BIOS settings for underclocking and undervolting at idle.
The power draw was an issue for me, but I realised that I am not going to see meaningful power consumption comparisons for all the different brands of card available in retail against the reference design. I could easily end up with one like the Powercolor that consumes almost as much as the 4850.
In the end I gave up and ordered a 4670 instead.