Radeon HyperZ In Open-Source On Older Hardware

Right now patches are still needed against the Linux kernel (the Radeon DRM driver) and Mesa in order for there to be HiZ/HyperZ support in the R600g driver, which is the Gallium3D driver supporting from the Radeon HD 2000 series through Radeon HD 6900 series. Patches in various forms for HiZ have been floating around for the past year, but nothing has managed to work its way into the Linux kernel and Mesa repository.

Earlier this month the HyperZ work was re-based by Jerome Glisse atop the latest Linux kernel DRM and Mesa code-base, with the R600 2D tiling work included. I was tempted to test that work, but initial indications are that the patches are still a bit buggy. Meanwhile, there has been the mainline support for HyperZ on the R500 series (Radeon X1000) and earlier.

It has been a while since last testing HyperZ on R300g, so I decided to do so with a Mesa 8.0 snapshot and two R500 class GPUs. The Radeon X1800XL and Radeon X1800XT were tested with and without HyperZ enabled. Using the RADEON_HYPERZ environment variable can test the HyperZ support for the older Radeon ASICs. Swap buffers wait was disabled and the two graphics cards tested with the only difference between testing runs is toggling the Radeon HyperZ support.