Thats hardly a quantitive measure though is it? Unless your encoding the exact same source material to the exact same end quality, how is a comparison going to be valid? I'm suggesting that to see which hardware is faster, you would ideally use the same encoder on each. In practical terms though thats probably not going to be possible since the software will be targeted specifically for the architecture of the hardware its running on. So the next best thing is simply to take the same source material and ensure you are using the same quality settings to encode it.