How to fix high power consumption on a hybrid-graphics laptop

I have a hybrid Radeon 6600M/Intel laptop, and I've installed the Ubuntu beta 2, hoping that I'd get a better battery life but I still seem to be getting high power consumption.

With radeon blacklisted, I'm still getting ~23W of power consumption. I get ~5 hours on Windows compared to <2 hours on Ubuntu. What can I do to decrease power consumption?

Solution 1:

On a hybrid Intel/AMD system, blacklisting radeon won't actually turn off the discrete Radeon card; it'll be in a lowish-power state because it's not doing anything, but it won't be off.

In order to actually turn off the card you need to have both intel and radeon loaded so that the vgaswitcheroo infrastructure gets initialised, and then you can run

echo OFF | sudo tee /sys/kernel/debug/vgaswitcheroo/switch

which will turn off any GPUs that vgaswitcheroo thinks are unused; in this case, it'll be your Radeon. You'll need to do this each boot; it's not persistent across restarts.