PilotMark 1.0 ReadMe
By Darrin Massena (darrin@massena.com)
22 Aug 96

I received mail from Luiz Coutinho (coutinho-lf@isottcc.med.ge.com) in
which he claimed to have discovered (through some ingenious hardware
hacking) that the memory bus on Pilot 1000 and 5000 devices runs only
8 bits, half the bandwidth of a 1 meg upgraded Pilot!

How could this be? Skeptical, I wrote a benchmark program (PilotMark)
to verify or deny this claim. My findings? A 1 MEG UPGRADED PILOT PERFORMS
MEMORY OPERATIONS AT OVER TWICE THE SPEED OF A NORMAL PILOT 1000 OR 5000.
Install PilotMark on your Pilot and see for yourself.

Like any benchmark results PilotMark's numbers should be taken with a large
grain of salt. Applications perform a mix of memory reads and writes and
instruction executes. Instruction execution itself is not affected by the
bus speed but instruction _fetching_ is. What this means is that a small
but slow instruction that isn't fetching additional data (e.g., a divide)
is affected less by bus speed than one that mostly reads or writes memory
(e.g., a memory copy). The impact on every program will vary depending on
their instructions and memory accesses. Some programs will be unaffected
while others will be literally twice as slow on a 1000 or 5000 than on a
1 meg upgraded Pilot. Keep in mind that performance is not an absolute:
if the speed of your Pilot seems fine to you, then it is!

This has great implications across the board. An important one is that
software developers must test their apps on both standard and upgraded
devices to be sure performance and timing is true and what they expect it
to be.

Recommendation for prospective Pilot buyers: unless you're strapped for
cash, consider buying a Pilot 1000 and upgrading it to 1 meg rather than
buying a Pilot 5000. You'll get twice the memory and for some applications
twice the speed.

P.S. Thanks to Luiz for the great tip!

