The first test run was Nexuiz, which is a now defunct open-source game but with other drivers has proven to offer similar performance between operating systems. With the same i7-4770K system with HD Graphics 4600, the Windows 8.1 configuration was almost twice as fast as Ubuntu 14.04 LTS with its latest Intel stable experience: Linux 3.13 and Mesa 10.1 as will be shipped next month in the Ubuntu 14.04 release. The Linux 3.14 and Mesa 10.2-devel configuration is not known to offer any major breakthroughs for HD Graphics 4600.
With the OpenArena 0.8.8 game, the performance between both operating systems were comparable with frame-rates and frame latencies.
While Mesa 10.0/10.1 allows OpenGL 3.3 support for Intel Haswell graphics, the Heaven and Valley tech demos were not running "out of the box" on Ubuntu 14.04 LTS.