I hope there's some power management stuffed somewhere in these new drivers or coming soon. I plan on buying a new Haswell notebook in the Fall and it will likely have Nvidia graphics since it's hard to get 1080p screens at 17-inches without a dedicated GPU in the configuration. Things are looking good!
Did anyone actually read the changelog? To quote:
This isn't proper Optimus support yet, it's for using the NVidia card *all the time* to render *everything*.Quote:
Added initial support for RandR 1.4 Provider objects with the Source Output capability, which can be used to render the desktop on an NVIDIA GPU and display it on an output connected to a provider with the Sink Output capability, such as an Intel integrated graphics device or a DisplayLink USB-to-VGA adapter. See the README for details.
Bumblebee: intel driver does basically anything, select apps are run off the nvidia card, otherwise the card is off.
Proper Optimus: Seamless transition back and forth as needed
This: Nvidia GPU is always rendering everything, but its the blob so it has the right PM bits set and available so you'll get the same battery life (and performance) as if you just didnt have the intel card.
FYI, looks like there maybe a vdpau bug with XBMC with these drivers BTW (at least with a GT-520 card).
In some notebooks bumblebee can successfully turn off the Nvidia chip while the Intel core does all the graphics rendering, so the discreet core never actually starts up until explicitly told to do so with optirun.
With Nvidia's driver both are running at the same time, and I think you underestimate the power drain of the Nvidia chip. :p