It all started a few weeks ago when Asus claimed to have full DirectSound 3D support on their Xonar DX and D2X soundcards, including EAX 5. Creative immediately rebutted, saying that NOBODY can do true EAX 5 (or in fact anything over EAX 2, which dates back to Soundblaster Live) except them.
However, Asus stuck by their guns, and with a combination of driver optimizations and software tweaks, they were able to manage DirectSound 3D in Vista (something Creative offers on their X-Fi cards using software that converts D3D calls to OpenAL, which still has access to hardware functions on soundcards) as well as EAX 5, using the CPU to process the audio.
Tech Report have the first review of this card, and the results are impressive. At just $90 or so, there really is no reason to get an X-Fi over a Xonar.
I have been working on a “X-Fi in Vista” article for a while (the software isn’t easy to use, so it’s been a long time coming), and I can see why Tech Report was so impressed. I’ll try to get a hold of one of these to do a full review of our own. In the mean time, go ahead and read TR’s review, knowing that they are the 2nd best hardware review site on the net ;)