Quote Originally Posted by chrismine View Post
The problem is solved by switching off Background Blur from the Search option in the Unity Tweak Tool as per the post #8 above.
A simpler way to avoid the 13.10 blur code is:

Add to /etc/environment

I don't have unity-tweak-tool installed (it's hurge) for any other reason.

The new blur code doesn't work as expected on many hardware configurations including mine. For whatever reason development chose to emulate some hardware functions in software which is much slower. The above change puts the function back in the much faster hardware.

I think launchpad bug #1222602 has some more detail.

At 78 my vision is blurry enough I don't need deliberate blur in ubuntu.