Phoronix posted an article that the Intel Graphics on Linux is still behind Windows

Now that I finally have Sandy Bridge graphics working under Linux, thanks to another H67 motherboard and Core i5 2500K processor from Intel that don't exhibit the earlier problems, there's many Linux benchmarks available. Overall the Core i5 2500K graphics under Linux with the latest kernel / DDX / Mesa are fast, for being Intel integrated graphics and much improved over their previous generations of hardware. But how do these first-cut Intel Linux Sandy Bridge drivers compare to the drivers of the same age under Windows? In this article are benchmarks comparing the Intel Core i5 2500K graphics performance under Microsoft Windows 7 SP1 and Ubuntu 10.10.

  Intel Graphics On Linux Still Behind Windows