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. 13-Way Low-End GPU Comparison With AMD's AM1 Athlon
  2. ASUS AM1I-A: A Mini-ITX Board For Socketed Kabini APUs
  3. Mini-Box M350: A Simple, Affordable Mini-ITX Case
  4. Overclocking The AMD AM1 Athlon & Sempron APUs
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. Git 2.0 Test Releases Begin With Many Changes
  2. Wine 1.7.17 Works On Its Task Scheduler, C Run-Time
  3. The Improv ARM Board Still Isn't Shipping; Riding A Dead Horse?
  4. Debian To Maintain 6.0 Squeeze As An LTS Release
  5. Wasteland 2 Is Finally Released For Linux Gamers
  6. FreeBSD Advances For ARM, Bhyve, Clang
  7. Ubuntu 14.04 LTS "Trusty Tahr" Officially Released
  8. Ubuntu 12.04 LTS vs. 14.04 LTS Server Benchmarks
  9. QEMU 2.0 Released With ARM, x86 Enhancements
  10. Running The Unity 8 Preview Session On Ubuntu 14.04 LTS
  11. R600 Gallium3D Disables LLVM Back-End By Default
  12. Fedora 21 Gets GNOME 3.12, PHP 5.6, Mono 3.4
Latest Forum Discussions
  1. Suggestions about how to make a Radeon HD 7790 work decently?
  2. The GNOME Foundation Is Running Short On Money
  3. Updated and Optimized Ubuntu Free Graphics Drivers
  4. Radeon 8000M problematic on Linux?
  5. Linux Kernel Developers Fed Up With Ridiculous Bugs In Systemd
  6. After Jack Keane, RuseSoft will briing Ankh 3 to Linux through Desura
  7. Suspected PHP Proxy Issue
  8. Change installation destination from home directory