Phoronix compared the Intel HD graphics performance of SteamOS and Ubuntu 13.10
When Valve announced the public release of the beta for SteamOS 1.0 "Alchemist" on Friday they listed NVIDIA graphics as a hardware requirement, but I showed that AMD Radeon graphics with Catalyst would work and it's possible to get Intel graphics working (or the open-source graphics drivers in general) through a minor change to the Linux-based SteamOS kernel parameters. After that I ran some benchmarks and here are a few performance results comparing SteamOS 1.0 Beta to Ubuntu 13.10 with Intel HD Graphics.SteamOS vs. Ubuntu 13.10 - Intel HD Graphics Performance
When enabling support for kernel mode-setting with the SteamOS kernel, Valve's Debian-based Linux distribution worked just fine. For the Intel HD Graphics support there is the Linux 3.10 kernel and Mesa 9.2.2 as the key graphics driver components worth mentioning. If you're planning to use SteamOS or Linux in general for playing any Steam games, you will really want an Ivy Bridge processor or ideally a Haswell graphics processor. Broadwell will also be really great for Linux gaming when the next-generation CPUs premiere. As of my most recent testing in November, the Intel Linux graphics performance is close to Windows 8.1 generally for OpenGL games. I wouldn't recommend any Intel Sandy Bridge CPUs though since the performance has improved a lot since then with IVB/HSW CPUs but also that the Intel Linux driver for SNB doesn't support OpenGL geometry shaders and Intel's Linux developers are focusing less upon upstream improvements to Sandy Bridge specific code. Ivy Bridge hardware and newer is what you will need with Mesa 10.0+ to have open-source OpenGL 3.3 support.