From: utzoo!decvax!ucbvax!info-vax
Newsgroups: fa.info-vax
Title: Re: DEC-20 vs. VAX
Article-I.D.: ucbvax.7973
Posted: Fri Jul  9 19:04:13 1982
Received: Sun Jul 11 03:14:08 1982

>From MILLER@SRI-NIC Fri Jul  9 19:00:07 1982
	When I was at DEC, I had the opportunity to perform
an extensive benchmark on floating point FORTRAN on a
2060 and a VAX.  Hardware config's were:

2060:	512 Kwords memory
	2 RP06 Public Structure

VAX:	2 MegaBytes memory
	1 RP06 file system

	There were five programs to be run.  They produced a
moderate amount of printouts, about 200 pages as I recall.
I cannot remember the exact timings, as this was close to
three years ago, but in four out of five cases, the 2060
was ahead of the VAX.  The best case was a 28% performance
improvement on the 2060 vrs the VAX, and the worst case was
12% slower.

	As I recall, the total benchmark ran 25% faster on the
2060.

	As for relative performance, the PDP-10 can queue up
multiple page transfers at a time.  The VAX is limited to
1 I/O operation at a time (I.e., queue, wait, queue, wait, etc.)


	I have also seen a relatively small user base bring
a moderate size VAX to it's knees.  8 users should not be
able to do this, especially since they were not doing
anything exotic.

	On the whole, if you want a batch oriented Fortran
machine, I'd say the VAX is a win.  However, if you want
good performance on batch and timesharing, plus a pretty
sexy Fortran machine to boot, I'd go with a PDP-10.

-HWM
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