I have a hybrid Intel/Nvidia system using bumblebee on Ubuntu 12.10 with specs: Clevo W150HR, SB i7-2720qm, 8GB RAM, 128GB Crucial M4 SSD + 500GB HDD It is reported to use software rendering (through Gallium driver) rather than accelerated through the intel HD driver.
Reinstalling the intel driver has no effect:

sudo apt-get install --reinstall xserver-xorg-video-intel    

The result is a rather sluggish desktop. Is there any way to blacklist the gallium driver? Or force the intel driver instead?

Edit 1 - Ubuntu 12.04 shows the driver as Intel SandyBridge out of the box, but 12.10 does not even after running the above command.

Edit 2 - Xorg.0.log shows:

(--) intel(0): Integrated Graphics Chipset: Intel(R) Sandybridge Mobile (GT1)
(WW) intel(0): Disabling hardware acceleration on this pre-production hardware.

Edit 3 - It turns out that SandyBridge rev.7 systems are known to be unstable per this link. Accordingly in the xserver-xorg-video-intel if it detects this rev. it disables it with the warning in above log.