Intel D975XBX: Intel brings their Bad-Axe to Market

Audio Performance

We limited audio testing to the Rightmark 3D Sound version 2.2 CPU utilization test and tested with sound enabled to show the performance effects on several games. The Rightmark 3D Sound benchmark measures the overhead or CPU utilization required by a codec or hardware audio chip.

The Sigmatel STAC9221D codec on the Intel D975XBX board does not fully support 3D Hardware, EAX1, or EAX2 modes as the other on-board codecs do at this time. Consequently, its performance is highly dependent upon the CPU and gaming support will be limited to generic OpenAL or 2D modes.

The Sigmatel STCAC9221D codec has extremely high CPU utilization rates in the 2D audio tests when utilizing 32 buffers, which is a minimum requirement in most of today's games. The BlueGears/HDA Mystique 7.1 Gold still has the highest overall utilization rates of the audio solutions tested. BlueGears has confirmed a new driver release that will offer improved performance in several areas. The Realtek R1.29 driver release has improved CPU utilization rates over previous releases. This driver set has been supplemented with the R1.30 release that will be tested shortly. The Sound Blaster X-FI has the lowest rates with the Sound Blaster Live! 24-bit solution on the Gigabyte board following closely. Let's find out how these results translate into real world numbers.

The audio performance numbers are interesting as the Sigmatel 9221D creates frame rate losses consistent with the other solutions even though the audio output is in 2D mode. This is primarily due to the design of the drivers and codec that rely heavily on the CPU to process the audio streams. Serious Sam II has an average loss of 45%, Half Life 2 at 26%, Splinter Cell at 12%, Battlefield 2 at 13%, and F.E.A.R. at 6%. The surprising number is the performance of the Sound Blaster X-FI in Serious Sam II with a 29% decrease in frame rates at this time. Serious Sam II sounded bright and tinny on the Sigmatel 9221D and did not offer an enjoyable game playing experience in Splinter Cell, HL2, BF2, or F.E.A.R. where 3D sound is a must. While the audio output quality of the Sigmatel 9221D still exceeds that of the Realtek ALC850 in games, it would not be our choice for a true gaming solution.

Obviously, if you are a serious gamer, then a dedicated sound card is still a requirement to ensure consistent frame rate averages across a wide variety of games. We noticed in our Battlefield 2, Serious Sam II, and Half Life 2 testing that the ALC882M solution would stutter in intensive scenes, creating frame rates in the low teens momentarily. We will be testing the Realtek R1.30 drivers in our next article to see if the minimal frame rates and stutter issues have been improved.

The included Intel Audio Studio software offers excellent configuration options in an impressive yet easy to use package. The Sigmatel 9221D audio solution displayed excellent sound characteristics in music, video, and DVD playback throughout our testing and should seriously be considered as the main audio component if gaming is not your priority. However, while the audio output quality in games was acceptable, the lack of basic EAX compatibility and performance degradation is not.