With the problems of DAE -6042 errors, we decided to provide more options for "tuning" your PCI usage with HD. Using more chips lowers the amount of PCI overhead. As a result, it allows each DSP to have more "breathing room" (since each has to process fewer audio tracks individually). Instead of having to process 32 or 48 streams in a given amount of time, lowering to 24 or 16 streams allows each DSP to be more resilient to PCI bursts taking too much time. Therefore, the actual traffic on the PCI bus isn't any different for the same number of audio tracks, but the "load" on each DSP is lighter.If you are not having -6042 problems, then it makes sense to use large voices-per-DSP (fewer DSPs used for the audio engine). But if you are running into -6042 "PCI bus too slow" errors with a video card, Unity, an expansion chassis, or some other PCI card, then using fewer voices per DSP can allow you to get just as many tracks at the expense of using more DSP for the audio engine.