1. Computers
  2. Display Drivers
  3. Graphics Cards
  4. Memory
  5. Motherboards
  6. Processors
  7. Software
  8. Storage
  9. Operating Systems


Facebook RSS Twitter Twitter Google Plus


Phoronix Test Suite

OpenBenchmarking.org

AMD R600g Still Tackling Hierarchical Z

AMD

Published on 05 June 2012 09:29 PM EDT
Written by Michael Larabel in AMD
36 Comments

While patches have been around for more than one year to support Hierarchical Z on the ATI/AMD R600 open-source driver, the Gallium3D support still hasn't been merged.

Patches have been around for over one year and while the Radeon DRM kernel driver changes have been made, the Mesa/Gallium3D changes for user-space are still missing out. Hierarchical Z, or more easily known as HiZ, is what allows to-be-rendered pixels to be checked against the z-buffer before hitting the rendering pipeline to know whether the pixel can be potentially discarded early.

HiZ has been around for ages and the support is all set for the R300g driver and has existed on the Intel driver, but the mainlining of the HiZ R600g support has been stagnant.

As the first Mesa support update in four months, Jerome Glisse put out a new version of his R600 HiZ Mesa patch as part of this BugZilla comment. Jerome's "r600g-add-htile-support-v4" does "rebase on top of lastest mesa, disable CB export when clearing htile surface to avoid wasting bandwidth" and he mentions "this one actually improve[s] performance." Sadly it's not in Mesa master but rather his own personal FreeDesktop.org directory, but for those who want it, it's there. This patch amounts to about 400 lines of code and uses HTILE setup and Fast Z clear, but doesn't yet take advantage of HiS.

When speaking of not-merged-or-enabled open-source Radeon driver work, with the Linux 3.5 kernel it still doesn't enable PCI Express 2.0 support by default. PCI-E 2.0 can really boost the Radeon driver performance.

Latest Linux Hardware Reviews
  1. ASUS AM1I-A: A Mini-ITX Board For Socketed Kabini APUs
  2. Mini-Box M350: A Simple, Affordable Mini-ITX Case
  3. Overclocking The AMD AM1 Athlon & Sempron APUs
  4. AMD Athlon 5350 / 5150 & Sempron 3850 / 2650
Latest Linux Articles
  1. Ubuntu 12.04.4 vs. 13.10 vs. 14.04 LTS Desktop Benchmarks
  2. AMD OpenCL Performance With AM1 Kabini APUs
  3. A Quick Look At GCC 4.9 vs. LLVM Clang 3.5
  4. Are AMD Athlon/Sempron APUs Fast Enough For Steam On Linux?
Latest Linux News
  1. FreeBSD Advances For ARM, Bhyve, Clang
  2. Ubuntu 14.04 LTS "Trusty Tahr" Officially Released
  3. Ubuntu 12.04 LTS vs. 14.04 LTS Server Benchmarks
  4. QEMU 2.0 Released With ARM, x86 Enhancements
  5. Running The Unity 8 Preview Session On Ubuntu 14.04 LTS
  6. R600 Gallium3D Disables LLVM Back-End By Default
  7. Fedora 21 Gets GNOME 3.12, PHP 5.6, Mono 3.4
  8. Fedora Workstation Is Making Me Quite Excited
  9. Maynard: A Lightweight Wayland Desktop
  10. Chromium Browser Going Through Growing Pains In Ubuntu 14.04
  11. KDE 4.13 Is Being Released Today With New Features
  12. Trying Out Radeon R9 290 Graphics On Open-Source
Latest Forum Discussions
  1. The GNOME Foundation Is Running Short On Money
  2. Updated and Optimized Ubuntu Free Graphics Drivers
  3. Radeon 8000M problematic on Linux?
  4. After Jack Keane, RuseSoft will briing Ankh 3 to Linux through Desura
  5. Suspected PHP Proxy Issue
  6. Linux Kernel Developers Fed Up With Ridiculous Bugs In Systemd
  7. Change installation destination from home directory
  8. Bye bye BSD, Hello Linux: A Sys Admin's Story