Yes, the SW20 is an SB Pro compatible card so its best on an older 086 system. I have an SB16 and Roland general midi SCC-1 card for the newer system. The sensible thing would be to get an SB AWE32 but I am afraid I am a sucker for hardware.
Keropi, I wonder whether T2PC will work on a P2 400Mhz system? If so, I may not bother with a 486 based system.