The graphics core of new CPUs used to have issues on Linux at launch but recently this has become much less of an issue.  The newly released Iris Pro on the 5770C follows this trend as you can see in the benchmarks at Phoronix.  The OpenGL performance is a tiny bit slower overall on Linux, apart from OpenArena, but not enough to ruin your gaming experience.  With a new kernel on the horizon and a community working with the new GPU you can expect the performance gap to narrow.  Low cost gaming on a Linux machine becomes more attractive every day.

"Resulting from the What Windows 10 vs. Linux Benchmarks Would You Like To See and The Phoronix Test Suite Is Running On Windows 10, here are our first benchmarks comparing the performance of Microsoft's newly released Windows 10 Pro x64 against Fedora 22 when looking at the Intel's OpenGL driver performance across platforms."

Here are some more Processor articles from around the web:

Processors