The best graphical experience with Ubuntu 15.04 and the ThinkPad W510 is currently only possible with the Nvidia binary graphics driver. On my ThinkPad I’ve installed the Nvidia binary driver – version 340.96 from nvidia-340 (proprietary, tested). However with the default settings my brightness keys stopped working. To get them working again, create the following file:
/etc/X11/xorg.conf.d/10-nvidia-brightness.conf
Section „Device“
Identifier „Configured Video Device“
Driver „nvidia“
Option „RegistryDwords“ „EnableBrightnessControl=1“
EndSection
After restarting the X server or the W510 you can adjust brightness by the normal function key combination.