T410 Optimus graphics fail to switch

[Tim M]

I have a T410 with the Nvidia Optimus discrete graphics and the Intel integrated HD graphics. I've noticed that the Optimus driver fails to switch from the Intel to the Nvidia on demand when an application requires it (such as a video game). Manually changing the global setting does not work either. The only way I can "force" the laptop to use the Nvidia graphics is to set the discrete graphics card as the default in the BIOS. Doing so defeats the entire purpose of switching graphics to conserve power.

Things seemed to break after either an Nvidia driver update or a Lenovo BIOS update. Are there any workarounds that will restore true switchable graphics capability? Having to toggle the Nvidia and and off via the BIOS seems silly.