Intel Broadwell HD Graphics 5500: Windows 8.1 vs. Linux
With the GpuTest Plot3D synthetic benchmark, Windows 8.1 started out 30% faster than Ubuntu 14.10 but when upgrading to the DRM code to be merged into the Linux 3.20 kernel, the Linux graphics ended up being 5% faster than Windows 8.1
With the demanding Furmark benchmark, Windows 8.1 was 14% faster across the board than all tested Linux combinations.
The Broadwell graphics started out poorly with GpuTest's simple triangle benchmark but when upgrading to Mesa 10.5-devel this synthetic test is now outperforming Windows 8.1.