Кстати, ради интереса протестируй свой АС97 прогой RightMark 3DSound 1.0 ( http://audio.rightmark.org/rus/index.html ) и скинь сюда результаты, скажем при использовании 32-х буфферов. Интересно посмотреть.
Пжалста:

Device: VIA AC'97 Audio (WAVE) (viaudios.sys)

Features:
DirectSound 3D Hardware: Yes
DirectSound 2D Hardware: Yes
EAX 1: Available
EAX 2: Available
EAX3: N/A
EAX4 Advanced HD: N/A


Rates:
dwMinSecondarySampleRate 100
dwMaxSecondarySampleRate 48000


Free buffers stats:
dwFreeHw3DAllBuffers 32
dwFreeHw3DStaticBuffers 32
dwFreeHw3DStreamingBuffers 32
dwFreeHwMixingAllBuffers 32
dwFreeHwMixingStaticBuffers 32
dwFreeHwMixingStreamingBuffers 32


Max buffers stats:
dwMaxHwMixingAllBuffers 33
dwMaxHwMixingStaticBuffers 33
dwMaxHwMixingStreamingBuffers 33
dwMaxHw3DAllBuffers 33
dwMaxHw3DStaticBuffers 33
dwMaxHw3DStreamingBuffers 33


Misc stats:
dwFreeHwMemBytes 0
dwTotalHwMemBytes 0
dwMaxContigFreeHwMemBytes 0
dwUnlockTransferRateHwBuffers 0
dwPlayCpuOverheadSwBuffers 0


Audio transfer speed (hardware): 4.545 Mb/sec.

PS Я уж понял что фигня все это... Но надо же помучать свое железо