[comp.dcom.modems] My VAX can't keep up to my Trailblazer

dave@onfcanim.UUCP (Dave Martindale) (08/30/88)

When outputting text from our poor old VAX 780 to a Trailblazer,
(through an Emulex CS-21, which emulates a DMF32) the VAX does quite
well - I get 1900 characters per second at 19200 bps.

However, uucp fares much worse, getting only about 1100 cps.  I know
that some of that is due to small packets and waiting for acknowledgements
and more context switches and the like, but at least when transmitting
there is still idle CPU left over, indicating that the modems or the
far-end machine is the bottleneck.  However, when receiving, the
peak transfer rate is a bit lower AND the VAX is 100% busy.
The CPU is the bottleneck.

Has anyone poked at either uucico or the tty driver or the DMF driver
to reduce the overhead on received UUCP packets?  Don't tell me to ditch
the 780 - we probably will when the lease runs out, but that's not for
another 2 years.

	Dave Martindale