EAX still broken in Realtek audio drivers
Back in November we explored EAX performance with onboard audio and discovered that Realtek's HD audio drivers weren't properly implementing occlusion and obstruction effects. These effects are a part of the EAX 2.0 spec that Realtek's codecs supposedly support, but they didn't work with the company's then-current audio drivers. Realtek hasn't responded to our numerous inquiries regarding the issue, and some readers have requested that we revisit the subject with the company's latest audio drivers. So we have.
Unfortunately, little has changed since November. We tested Realtek's latest 1.66 audio drivers in Windows XP with an EVGA 122-CK-NF68 motherboard that features an ALC885 codec chip, and EAX occlusion and obstruction effects still aren't working. This problem is easily observed with RightMark 3D Sound 2.3, but it also affects games, including Battlefield 2. That title makes particularly extensive use of occlusion and obstruction effects, and it's still unplayable in EAX mode with Realtek's audio drivers.
Since Windows Vista doesn't support EAX, this isn't an issue for that operating system. However, those planning to use onboard audio with Windows XP would do well to avoid Realtek codecs if proper EAX support is a priority.