IRQ sharing on PCI came with its own pains though which were sometimes harder to diagnose and fix. In the early 2000's I was recording and mixing music with DAWs on Windows 2000 and you always had to be very careful that your PCI ASIO sound card did not share resources with anything else or you got to deal with dropouts and glitches. Plenty of futzing around in BIOS setup and Device Manager, very flaky stuff.