Here are the important characteristics of sound cards:
Discrete sound cards have been made in ISA and PCI versions, but ISA cards are no longer available. All recent sound adapters, embedded or standalone, use PCI. The much smaller bandwidth of ISA limited ISA cards in many respects, including generally requiring that wavetable data be stored locally, placing an upper limit of about 16 on simultaneous sound streams, and making effective 3D audio support impossible. If you encounter an ISA sound card when stripping an older system for spares, pitch the ISA card. It’s not worth keeping.
FM synthesis is no longer used in current sound cards. All current midrange sound cards use wavetable synthesis, and some expensive sound cards use partial waveguide synthesis. The quality and features of wavetable synthesis vary depending on both the processor and the quality and size of the wavetable samples, with more-expensive cards producing better synthesis, as you might expect.
Each MIDI interface supports 16 channels, each corresponding to one instrument. Low-end sound cards have one MIDI interface, allowing up to 16 instruments to play simultaneously. Midrange and high-end sound cards usually have dual MIDI interfaces, allowing up to 32 simultaneous instruments. Some high-end sound cards, such as the Creative Labs Sound Blaster Live! Platinum, use a triple MIDI interface, which allows up to 48 simultaneous instruments. In general, ...