I have done some more testing, and the results are mysterious to me.
The test: I have some drums playing on port 1 cha 1,2,3. I have some strings playing on port 1 cha 14,15,16. The polyphony is 50-70 (layered stereo sounds eat up a lot) and cpu is about 30. (In sampler settings polyphony is 160.)
The timing of the drums at this point is ok.
Now if I put either the drums or the strings on another port, the timing of the drums will be notibly worse.
This looks strange to me, as one would assume that spreading the load to different ports would be better or at least the same.
In my previous post, I thought that it was the continuous controllers that were causing the problem, but they are not. It is the number of voices that seems to be of importance here.
I would be very pleased if any of you would perform the above test if you have multiple midi inputs to your GS.
I have GSt160 on a dedicated PC(750mHz) Midi and audio for GS is WaMi rack24.
All software is newest versions and OS is windows 98se.