[comp.unix.sysv386] I/O access vs. Memory access

keith@richard.csc.ti.com (Keith Sparacin) (01/19/91)

Are there performance problems related to accessing i/o memory vs.
non-i/o memory on Intel based computers running Unix?  Rumor has it that
i/o accesses take longer than memory accesses due to memory protection
schemes.  Can anyone provide any information on this subject?  Thanks.

Keith Sparacin      (keith@csc.ti.com)
Texas Instruments