[Simh] Reference performance benchmarks

[Jacob Goense]

I'm running simh in rather tight corners. Mostly VAX/780 and PDP-11/70
with V6 or BSD. Simh runs in a browser, or, I have (too) many of them
on underpowered Asus Eee PC's. Any tips on how I can check if I have
taken things too far? Like minimum values to look for in SHOW CLOCK,
or any tools I can run that can be referenced against same on real kit.

I run into the same question on the I/O end. During the installation
of v6 I can do dd if=/dev/mt0 of=/dev/rk1 bs=2048 count=1000 skip=1025
and it is done in a second on machine that is doing nothing else. With
simh running in a browser on a small busy machine it can take up to an
hour. I have no idea how to gauge how far this is off from real kit.