We tested the X-Fi with several games - Doom 3 (with the EAX patch), Battlefield 2, Half-Life 2 and Painkiller. Battlefield 2 is the only game of the bunch to actually support the new features of the X-Fi, allowing the full 128 sound streams, rather than the 64 of the Audigy series of cards. This means more guns, tanks, ambient effects and voice communications at once.
Using speakers, all the games sounded great with plenty of punch, clarity and pinpoint spatial positioning. Doom 3 and Battlefield 2 had an eerie sense of really being in the thick of things.
In Battlefield 2, changing the sound settings from “High” to “Ultra High” (only available on X-Fi) produced a frame rate hit of about 5 frames per second. However, we doubled the number of voices being played at once from 64 to 128. The onboard X-RAM did a great job of doubling the audio output, but keeping the frame-rate hit to the bare minimum. However, to be honest we did not consciously notice any differences in the number of sounds being played - we were too immersed in the game, and the differences were incredibly subtle.
We anticipate that games coming out in the future will be making rather better use of the X-Fi-specific features - it rather appears like the features have been 'tacked on' to Battlefield 2. We look forward to seeing what games developers can do with the 64MB of RAM.
All in all, the gaming experience was a good one. Using headphone surround sound and decent pair of headphones, the experience was nothing short of fantastic.