Subject: Re: why do we do it
To: Sean Davis <email@example.com>
From: Johnny Billquist <bqt@Update.UU.SE>
Date: 08/22/2005 01:56:46
On Sun, 21 Aug 2005, Sean Davis wrote:
> On Mon, Aug 22, 2005 at 01:29:04AM +0200, Johnny Billquist wrote:
> > On Sun, 21 Aug 2005, Jochen Kunz wrote:
> > > On Sun, 21 Aug 2005 02:32:35 +0200
> > > Erik Bertelsen <firstname.lastname@example.org> wrote:
> > >
> > > > I wonder how long time a full NetBSD build takes on the slowest
> > > > hardware able to do the build itself :-)
> > > I suspect this would be a VAX 11/750: 0.65 MIPS.
> > > More common is a MicroVAX II: 0.9 MIPS.
> > > There is the even slower VAX 11/730: 0.3 MIPS, but IIRC it is not
> > > supported by NetBSD.
> > >
> > > I leave it to your homework to calculate estimated build times based on
> > > the MIPS numbers. ;-)
> > I can also tell that on a VAX-8650, it takes a little over a week
> > nowadays.
> > In speed comparision, a VAX-8650 is about 6 VUPS (maybe a bit more), while
> > the 11/750 is the same 0.65 VUPS. That would leave us somewhere around 11
> > weeks. Now, an 11/750 can't have more than 14 megs of physical memory (or
> > something like it), which means it will probably be even worse.
> Has anybody written anything to benchmark a machine in VUPS? I'd be
> interested to know how many VUPS an Athlon gets, or an Opteron ;)
Doubt there would be a point to it, since you don't have the same
instructions. VUPS is mostly meaningful to compare different VAXen, since
that will tell you how fast the same code would execute on different
machines. Binary code, that is.
The problems with the MIPS measurement is just that it used some C code
for reference, and when compilers got better at generating code, even a
VAX-11/780 became faster than one MIPS.
So when you depend on the result of a compiler, and use different
compilers, how do you tell the speed of the machine in relation to the
behavour of the compiler?
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: email@example.com || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol