After the R300g HyperZ support was sharply improved and enabled by default in Mesa at the beginning of the month, improved R600g HyperZ support also emerged.
After battling GPU command stream errors and months of troubles for open-source GPU driver developers, the HyperZ support for modern AMD Radeon GPUs was finally sorted out in this open-source Linux graphics driver.
The HyperZ feature to ATI/AMD GPU hardware consists of Z compression for minimizing the Z-Buffer bandwidth, fast Z clear, and a hierarchical Z-Buffer. This feature found in ATI/AMD graphics hardware for quite some time has been able to deliver sizable performance improvements for a range of OpenGL workloads.
With commits hitting mainline Mesa on Thursday, flushing and synchronization pattern was re-worked for R600g so that it matches the patterns when running the proprietary AMD Catalyst driver. Another commit added HTILE support to the driver, which had undergone sixteen revisions before being in a state for merging to mainline.
HyperZ isn't yet enabled by default for this Gallium3D drivers, but it's finally getting closer to being that way with these recent improvements. This work will be found in the next Mesa 9.1/10.0 release due out in H1'2013.