Hi, everyone; Rory here again.
First of all, I've already explained why I didn't test under Windows Vista, despite the fact that any issues with the drivers would likely surface in Vista. This article wasn't meant to compare the two cards from different manufacturers on every conceivable point -- rather, the purpose of the article was to determine whether there would be an audible difference between the two DSP systems when everything was working correctly. And, as you've read, I found that even though the Creative card had a slight edge when it came to the quality of its EAX effects, it's unlikely that you'd notice a difference while playing a game, unless you were specifically listening for one.
Regarding the possibility of a placebo effect being present, the duration of a human's auditory memory is about 3 seconds. Beyond that point, it's not possible to remember what something sounded like, unless we apply some objective terms. In testing the cards for this article, I always tested the Xonar first, then the X-Fi second, and took detailed notes of what I was hearing, right when I heard it. Objective terms that can be applied here to describe reverberant effects include audible distortion, multiple perceived decay rates from different sound sources, and clarity of the reverberant effects. So I think it's highly unlikely that a placebo effect existed -- due to the 3-second duration of auditory memory, it was easy to listen to each card with fresh ears and make notes about exactly what I heard.
As for performance impact of one DSP method over another, performance testing is usually reserved for our reviews of individual sound cards. However, given the interest in DSP effects similar to EAX and DS3D GX, it makes sense to include in-game testing in future sound card reviews, including CPU usage logging. Look for this in the upcoming review of the ASUS Xonar DX, which will take place whenever the replacement Xonar DX card arrives from ASUS (since the first sample had an issue.)
