As a practical matter, the CPU has to deal with IO as well, I don't believe any 486 systems could handle this.
DSP based systems struggled a lot with IO in the late 90s until faster SATA drives became ubiquitous. Lots of them used SCSI or exotic hardware cards to deal with large track counts.
DSP based systems struggled a lot with IO in the late 90s until faster SATA drives became ubiquitous. Lots of them used SCSI or exotic hardware cards to deal with large track counts.