Although I have the 16.04.1 Hardware Enablement (HWE) kernel, it appears there is an HWE version of xserver-xorg-video-intel I was not aware of, and which was not automatically selected with the HWE kernel. I will try that now (Using my current 16.04.1 LTS xenial HWE install).
Mesa: v12.0.6- 0ubuntu0. 16.04.1 xorg-video- intel: 2:2.99. 917+git20160325 -1ubuntu1. 2
xserver-
Although I have the 16.04.1 Hardware Enablement (HWE) kernel, it appears there is an HWE version of xserver- xorg-video- intel I was not aware of, and which was not automatically selected with the HWE kernel. I will try that now (Using my current 16.04.1 LTS xenial HWE install).
xserver- xorg-video- intel-hwe- 16.04: 2:2.99. 917+git20160706 -1ubuntu1~ 16.04.1