Hardware support multiple opens and mixes streams in hardware
Some available cards with the HWMIX tag
This is from a search of the matrix, and online stores.
Creative Labs cards using the emu10k1 drivers
SB Live! cards, elderly and used.
Audigy 4 cards
Audigy 2 ZS notebook cards
Audigy 2 cards.
Echo Corporation cards using the mia drivers
A new Mia Midi
Various TerraTec cards
Various Guillemot cards
Various AudioScience cards
Various Aureal cards
Various Labway cards
Everything except Xwave G7X "QS3000A", Xwave 4000 and Xwave 7100