Originally I had planned to do AMD Radeon benchmarks with the Catalyst binary driver similar to the seven-way NVIDIA SteamOS graphics cards benchmarks and the SteamOS vs. Windows 8.1 performance comparison. However, only with limited time before leaving the US for a few weeks on Monday, I wasn't able to complete the AMD tests in full.
I had discovered last weekend AMD GPUs do work with Catalyst on SteamOS, contrary to what's listed as hardware requirements by Valve, but only had time to run two graphics card tests on SteamOS. The rest of the tests will happen in mid-January when I'm back in my office and will be using the latest SteamOS packages at the time.
However, for those anxious to see some AMD SteamOS numbers or wish to run their own OpenGL performance comparison with the Phoronix Test Suite, I uploaded my initial SteamOS AMD benchmark results with the packaged Catalyst 13.11 beta driver to 1312155-SO-STEAMOSCA41. The initial results were from a Radeon HD 6770 and Radeon HD 6950 graphics card.