For this legacy testing, I decided to go back to Ubuntu 6.06 LTS, a.k.a. the "Dapper Drake" days. The proprietary Linux Catalyst driver back then wasn't even known as Catalyst but it was the pre-Orca days when the releases were just tagged as fglrx 8.xx.xx, ATI had no open-source strategy, there was no open-source 3D support for R300, the Mesa Gallium3D architecture wasn't yet conceived, and the Catalyst driver was very notorious among Linux desktop users. However, around 2006 was when the pre-Orca state was turning not too bad and the release found in Ubuntu 6.06 (fglrx 8.25) was around the time I had started the original "ATI Redblog" coverage. It's a good starting point.
After running the Phoronix Test Suite on Ubuntu 6.06 LTS, I moved forward to the Ubuntu 8.04 "Hardy Heron" release. It was the Long-Term Supper successor to the Dapper Drake and the first Ubuntu Linux release following the unveiling of AMD's new Catalyst "Orca" Linux driver. A.k.a. the point when AMD finally provided Radeon HD series proprietary Linux support, measurable performance improvements, and many other features as talked about in all of the Phoronix exclusive articles back in September of 2007 that began with the fglrx 8.41 driver preview. Ubuntu 8.04 LTS was also the first Ubuntu Linux release following the start of AMD's now-famous open-source driver strategy. With Ubuntu 8.04.4 LTS on the IBM ThinkPad R52, it was tested with the Catalyst 8.3 (fglrx 8.47.3) graphics driver as found in the Hardy Heron repository. Catalyst 8.3 is the first tests in this driver using the new "Orca" OpenGL driver since the revamp in September of 2007.
The third Ubuntu Linux release to receive a new round of testing was Ubuntu 8.10 "Intrepid Ibex", since it was the last Ubuntu Linux release that's compatible with the Catalyst Linux driver for R300 through R500 (Radeon X1000) GPUs. It was in March of 2009 that AMD dropped support for older hardware from their Catalyst driver under Windows and Linux. This was done so AMD could focus upon R600+ support. The Catalyst 9.3 release is not compatible with Ubuntu 9.04 due to X.Org Server and Linux kernel compatibility differences, so Ubuntu 8.10 was the last release tested with the binary blob. The Catalyst 8.10 (fglrx 8.54.3; the stock Intrepid binary driver for ATI) and Catalyst 9.3 (fglrx 8.59.2) releases were tested under Ubuntu 8.10.