Below instructions are old.
Laptop HP 4530s with RADEON 6490m I didn't make any bios updates. Make sure that the discrete graphics card isn't disabled in bios. Has clean installation of Linux Mint 13 64 bit If Intel Power Saving GPU mode is selected from "AMD Catalyst Control Center (Administrative)": Can have up to 4 hours 45 minutes of battery life. Temperature is very low. (Left side of touchpad is cool) Low fan noise level. (Fan runs on lowest level) If "High Performance GPU" is selected from "AMD Catalyst Control Center (Administrative)" Can have up to 2 hours 15 min of battery life. Medium fan noise level. Temperature is a bit higher than on Intel GPU, but way cooler than default Ubuntu installation drivers.