For the past few days at Phoronix we have begun looking extensively at the Intel Iris Pro 5200 graphics under Linux, since receiving the System76 Galago UltraPro. The Iris Pro 5200 are the new high-end Intel Haswell graphics that have 128MB of embedded video RAM on the die, which should yield a nice performance boost when properly implemented within the Intel Linux driver. Already our testing has found the Iris Pro performance on Linux has doubled with open-source driver improvements since Haswell's launch. Now we're out today with our first Intel Iris Pro OpenGL gaming benchmarks between Ubuntu Linux and Microsoft Windows 8 for this Intel Core i7 Ultrabook.
The most recent Linux vs. Windows benchmarks done at Phoronix for Intel Haswell hardware was done at the end of July when the results were still rather mixed. The Intel Windows OpenGL driver still tended to be faster than the open-source Linux driver. The Windows driver is also more feature-rich in supporting OpenCL and OpenGL 4.0 while the Linux driver isn't yet to feature parity with all of the hardware's capability, only handles OpenGL ~3.2 at the moment, and there's only an experimental OpenCL implementation. As another example, even OpenGL debugging is worse with Linux than Windows.
While two months ago the Windows vs. Linux driver results were mixed, it should be interesting to see how the OS comparison goes today given that Intel released a new Haswell graphics driver for Windows 7/8 last week and there's daily improvements being made to the open-source Linux hardware support. We're now up to the Linux 3.12 kernel being in early development along with Mesa 9.3 for the Intel DRI user-space driver.
For our Windows 8 testing, Microsoft Windows 8 Pro x64 was in use with all available software updates as of this week. The Intel Windows driver used during testing was the Iris/HD 188.8.131.5257 driver that was released on 11 September to succeed the original Haswell Windows driver from mid-May. On the Linux side we benchmarked both the Ubuntu 13.04 x86_64 stock configuration with the Linux 3.8 kernel, Mesa 9.1.4, and xf86-video-intel 2.21.6. After doing the stock testing of the latest Ubuntu Linux stable release, we then upgraded to the Linux 3.12 Git kernel (just before the 12.1-rc1 tagging), Mesa 9.3.0-devel git-395b941, and xf86-video-intel 2.99.902. This represents all of the latest Intel Linux graphics driver improvements that have been merged as of this week.
The System76 Galago UltraPro that was used for all of the Iris Pro testing is loaded with an Intel Core i7 4750HQ CPU, 8GB of system memory, and 120GB Intel SSD. The OpenGL graphics benchmarking under Ubuntu Linux and Windows 8 were facilitated using the Phoronix Test Suite software for carrying out enterprise-quality tests in a fully automated and reproducible manner. The results are hosted on OpenBenchmarking.org to allow for comparisons and other collaborative result analytics.