As reported earlier this week, HiZ support is now ready for Intel Sandy Bridge graphics under Linux with the Mesa driver. A set of more than three dozen patches were published that finalize this support for Sandy Bridge (Gen6) while the Ivy Bridge (Gen7) support is almost there but there are some performance regressions still being worked out by Intel's OSTC developers.
Back in September I published Intel Mesa HiZ performance benchmarks to show where this feature was at during Oktoberfest, which allows for some performance improvements. For more information on Intel HiZ support under Linux, see that earlier article.
In this article are new tests of the Intel HiZ support as of this week, when Chad Versace announced the Gen6 support is ready to be on by default. The 41 patches are currently on the Intel mailing list but should be merged to Mesa master soon. For the tests today I pulled them from Chad Versace's "HIZ" branch of Mesa 7.12-devel. Compared to the September HiZ benchmarks, the Linux 3.2 kernel is now being used plus the other Mesa advancements made in the past two months.
Testing was done on 22 November from an Intel Core i5 2520M Sandy Bridge system running the Ubuntu 11.10 64-bit operating system. For toggling the HiZ support, the INTEL_HIZ and INTEL_SEPARATE_STENCIL environmental variables were toggled. A variety of OpenGL benchmarks were tested under Linux with the HiZ support. Special thanks go out to SUSE's Egbert Eich for letting me run these tests from his flat while in Darmstadt.