R500 Mesa Is Still No Match To An Old Catalyst Driver

Written by Michael Larabel in Display Drivers on 9 April 2010 at 10:21 AM EDT. Page 1 of 3. 72 Comments.

We are in the process of conducting a set of tests looking at how the performance of Ubuntu Linux has evolved through their Long-Term Support (LTS) releases beginning with their first 6.06 "Dapper Drake" version followed by Ubuntu 8.04 "Hardy Heron", and then the Ubuntu 10.04 "Lucid Lynx" release that will be released by month's end. These benchmarks will look at how the performance of Ubuntu Linux has changed over the past four years, but first we deviated from our original plans to get a look at how the current open-source ATI R500 graphics driver in Ubuntu 10.04 provided by the Mesa stack performs against older proprietary ATI Catalyst drivers.

Just last month we delivered benchmarks comparing the Catalyst vs. Mesa performance with Ubuntu 10.04 using the latest open-source and closed-source drivers available for the ATI Radeon HD 4850 graphics hardware. This is similar to tests we have carried out in the past comparing two different drivers from the same point of time. What we really have not done up to this point is to see how the current open-source ATI graphics driver compares to a proprietary Catalyst driver for the past. This has not been done before, as there really is not a straightforward and reliable way to carry out such a comparison.

Older ATI Catalyst drivers will not work on newer Linux distributions due to the proprietary driver not supporting a more recent Linux kernel or X Server version. Changing around the open-source graphics driver version often means swapping out Mesa, the X.Org DDX driver, the Linux kernel for the respective DRM driver code, a compatible libdrm, and the open-source 2D EXA performance can also be affected by the X Server version. Further complicating matters is the fact that AMD routinely drops support for older GPU generations from the ATI Catalyst like they had done with the R200 support some time ago and then last year wiped out the R300/400/500 support from their driver, which limits the number of drivers and hardware selection that can be tested.

To at least get a better idea for how the current open-source ATI Linux driver stack is performing against the Catalyst Linux driver in older states, we looked at the performance in the different Ubuntu LTS releases. With a Lenovo ThinkPad T60 notebook that boasts an ATI Mobility Radeon X1400 (R500-based) we first tested Ubuntu 6.06.1 LTS with the proprietary driver stack that it offers through the Dapper Drake repository, which is fglrx 8.28.18 with an OpenGL version string of 2.0.5814. This closed-source Linux driver from May of 2006 brought many changes and in retrospect was an important milestone in the development of the Catalyst Linux driver. In H1'2006 there was not any working open-source 3D acceleration support for the ATI R500 GPUs so no open-source driver could be tested on Ubuntu 6.06 LTS -- it was more than a year before AMD even had an open-source strategy. Ubuntu 6.06.1 LTS uses the Linux 2.6.15 kernel and X.Org Server 7.0.0.

After testing out the fglrx 8.25.18 driver on Ubuntu 6.06.1 LTS we did a clean install of Ubuntu 8.04.4 LTS. Ubuntu 8.04.4 LTS uses the fglrx 8.47.3 driver with an OpenGL version string of 2.1.7412 and the Linux 2.6.24 kernel and X.Org Server 1.4.0.90. Ubuntu 8.04.4 LTS was released in April of 2008 and it was only around that time that the open-source R500 support started hitting 3D milestones and it was not until after the Hardy Heron release that it achieved 3D success and that the open-source stack would work with some games. Worth noting that between these Ubuntu LTS releases in 2006 and 2008 is when AMD unveiled their new Linux driver (with the 8.41.7 driver) in September of 2007 that was largely rewritten with its OpenGL component seeing great performance improvements and more of the code-base being shared between the Linux and Windows drivers. Their notorious driver also began catching up in other areas besides performance to the NVIDIA Linux driver and Catalyst Windows driver. It was also in September of 2007 that AMD got serious about open-source support by rolling out the RadeonHD driver and publishing code and specifications for their hardware ever since.

After testing Ubuntu 8.04 LTS with its default fglrx driver we then upgraded to Catalyst 9.3 manually, which was the latest proprietary driver update that supported the R300/400/500 ASICs. Unfortunately, driver bugs in that final R500 driver release barred us from carrying out any tests to see how the Catalyst driver support was with its farewell release.

Now with Ubuntu 10.04 LTS we have only the open-source driver to test. The Catalyst 9.3 driver that was the last to support the ATI Radeon Mobility X1400 graphics processor is not compatible with Ubuntu 10.04 (or even Ubuntu 9.10) due to the newer kernel / X Server. With our Lucid Lynx testing we ran our same OpenGL benchmarks using its default Linux 2.6.32 kernel (but it has the 2.6.33 kernel DRM), X.Org Server 1.7.6, xf96-video-ati 6.12.192, Mesa 7.7 configuration found in a clean Ubuntu 10.04 LTS installation.


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