Subject: Re: PC Emulation w/bochs - notes
To: Andy R <quadreverb@yahoo.com>
From: Richard Rauch <rkr@olib.org>
List: netbsd-help
Date: 01/07/2004 23:57:16
Re. http://mail-index.NetBSD.org/netbsd-help/2004/01/07/0019.html

For networking, it sounded like bochs was going to try to use your *real*
network interface directly, and make the emulated NIC look like an NE2000.
I didn't like that.  If I had been able to otherwise make bochs work for
me, I was going to try to make it use its emulated serial port to do SLIP
or maybe PPP to NetBSD.

CPU speed: On my AMD64, it definitely felt and acted a lot slower than a
real PII 266.  (Using a Knoppix 3.1 CD as a reference and assuming that bochs
would eventually have done something useful with Knoppix 3.1.)  It was much
slower on an 800MHz Athlon than on the AMD64.  I could about believe the
NetBSD boot message's claim about 20MHz (19.94 or so, actually) on the AMD64,
though at times I was skeptical that it was even turning in even that much
performance.  (^&

I wish that I had been able to boot the NetBSD installation that it created.
Then I could run a lot of familiar software and get a better idea of
performance.


pit: My guess is that if you gave it a useful tweak to mapping virtual
CPU performance to real performance (I forget the name of the option),
the keyboard delay would go away.  The default performance mapping is
assuming something like a 200MHz Pentium, and a 366MHz Celeron is going
to be much faster, so the timer for key repeating is going to be off.
This would probably be a better solution in general, since I/O rates
seemed to suffer terribly with "realtime" enabled.


-- 
  "I probably don't know what I'm talking about."  http://www.olib.org/~rkr/