We've also updated our testing to include Unigine's free Heaven 3.0 benchmarking tool. It works well as a graphics benchmark as it is GPU limited and is thus incredibly taxing on the GPU whilst placing the CPU under very little stress. It should therefore be repeatable for most users running half decent systems.
We run the full benchmark at 1920 x 1080, with 4x AA and 16x AF, and also ensure that tesselation is set to standard. For each card, we run the test three times and the scores shown are the average of the three runs.