Subject: Re: FreeBSD Bus DMA
To: None <perry@piermont.com>
From: John S. Dyson <dyson@freebsd.org>
List: tech-kern
Date: 06/11/1998 22:30:26
Perry E. Metzger said:
> 
> I've tried to use both. I haven't seen particularly much difference,
> frankly. I have heard your claim that FreeBSD compiles code "three
> times faster" and such, and frankly it isn't true. Claiming FreeBSD is 
> five percent faster under some conditions on a normal machine is
> within the realm of the believable, but I'm not even certain that that 
> is true.
>
You are misstating my claims, and I hope you meant to by mistake, becuase
otherwise your ethics should be challenged.  Didn't I say that our
compiles are 3 times faster?  I thought that is what I said.  BTW,
they are.  (Okay, they might be 2.5X or somesuch.)  Of course I am
talking about a huge project, about the size of a make world, and
I qualified it as such.  All this shows is that you didn't experience
something that I know that someone else has (and does.)  We just
want our compiles to  take less than 1.5 Hrs.  Going from 1.5Hrs
to 40min is a big big jump, and certainly worth changing the
build machine.

If you do a c compile of a single file, I could even imagine no
difference or worse.

> 
> > There is a significant performance difference between the two OSes,
> 
> No there isn't. They're virtually the same under most realistic
> conditions. I'm sure you could contrive some conditions that aren't
> realistic, as could I.
>
Well, I guess that you just aren't able to see the difference, and
if you don't set FreeBSD up correctly, I guess performance can be
kind-of blah.  Note that FreeBSD and NetBSD can be identical
in performance if all you are doing is a for loop with nothing in it.

> 
> > and to discount FreeBSD/Alpha as being a NetBSD kernel is not accurate.
> 
> Well, right now, it is a NetBSD kernel so far as I know.
> 
How long did you guys use another OS to bootstrap your own?  FreeBSD
cannot use a NetBSD kernel in prduction, because it would not
meet expectations.  There is NO released FreeBSD/Alpha kernel right
now, but that statment is vacuous when no such claims are made
yet, isn't it?

If you are used to stagnation, then I can understand you view,
but FreeBSD isn't stangent.

-- 
John                  | Never try to teach a pig to sing,
dyson@freebsd.org     | it just makes you look stupid,
jdyson@nc.com         | and it irritates the pig.