Windows XP forum: Realtek AC97 Audio

''The ''MS GS Wavetable SW Synth'' is a software based synth that will not allow
you to use the MIDI In capabilities of your Sound Card adequately. Typically,
this synthesizer has a lag of about 100 milliseconds (1/10th of a second)
from the time you start playing a note until the time you hear it. This makes
it not very useful for this type of application.

You would need to use your Sound Card's proprietary MIDI Driver instead of
a 'generic' 'universal' driver. If it is not available because it is not
installed, please consult with your Sound System's documentation to find
out which Driver should be used for MIDI.

If the only driver that works with your soundcard/soundchip is the ''MS GS
Wavetable SW Synth'', then that's really not good. If MIDI is important to you,
you may need to get a different soundcard. But contact your computer or
soundcard manufacturer first and see what they say.''

This is a direct quote from this URL:http://www.voyetra.com/site/kb_ftp/1694005.asp
which you might want to check out.

The MS wave table midi driver is included with the Windows system. It uses the central processor to very accurately synthesize very realistic musical instrument sounds in producing audio output from midi files. If you are only listening to midi files, this driver is very good for producing very realistic music from midi files. However, if you wish to produce midi music by inputting midi signals from a musical keboard or other midi instrument, you will find the millisecond delay mentioned very disconcerting. Most of us are listeners, not musical performers, and the driver is just fine for listening.

MPU-401 driver is for an external synthesizer with that specification. If the MS GS wave table driver works, stick with that for listening. Almost all midi software recognizes this driver. (the piano and guitar sounds are excellent)