_UNIX_Today!_

david Fridley david at psitech.UUCP
Sat Sep 9 01:12:50 AEST 1989


> volunteering! :-) ):  what do *you* think is important in a UNIX
> benchmark?  How do I compare Machine A (with hardware and software
> configuration of 'A') to Machine B with its H/W configuration of 'B'?
> 
I have a simple, easy to run, easy to understand bench mark that wants to be
run on unix machines.  For now lets call it the wait for echo test.  Set up
a task connected to one of the serial ports that will send out a character,
wait for it to be echoed, and then send out the next character of a 100K file.
Make the baudrate for the port something that is high, like 38400, but it needs
to be a baudrate that can be setup the same for all machines tested, so maybe
9600.  The serial port connector would connect the the TX line to the RX line
(Pin 2 to Pin 3 on a 25 pin connector) and do what ever on the control lines.
The result of this test would be a time to transfer the file, which can be
divided by the file size to yeild the effective baudrate. Another test would
be to run the wait for echo test on each of several serial ports at the same
time, and reporting the average effective baudrate as a function of the number
of processes.

What does this show? Well first off, it shows that UNIX is not a real time
operating system because the results for this test are far lower than the real
baud rate.  It also shows things like the latency time of the task switching
facility, and the raw speed of the machine.  The real feature of this test
is the reality of it, I know the difference between 9600 baud, and 2400 baud.
Drystones and Wheatstones are usefull benchmarks, but most people do not
have a good idea how that translates into things that they work with.  Other
bench marks could be how long it takes to compile the X - Windows distribution,
or backup your 320 megabyte hard disk onto diskettes.

-- 
david.
DISCLAIMER: If it's important have a backup.  If it ain't broke don't fix it.
Proceed at your own risk.  My oponions are MY own.  Spelling does not count.
My fondest dream is to leave this planet.



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