Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!ucsd!ucbvax!hplabs!hpda!hpcuhb!hpcuhe!linley
From: linley@hpcuhe.cup.hp.com (Linley Gwennap)
Newsgroups: comp.arch
Subject: Re: Snakebytes (long -- and poisonous?)
Message-ID: <32580008@hpcuhe.cup.hp.com>
Date: 28 Mar 91 18:57:03 GMT
References: <69465@brunix.UUCP>
Organization: PA-RISC Marketing Central
Lines: 21

(Donald Lewine) asks:
Are the new PA machines binary compatible with the old ones?  Reading
the press, it sounds like there are new instructions in the new 
machines so that while the old programs will run, the full performance
will not be achieved unless you recompile.  Is this true?
----------

The Series 700 systems are fully binary compatible with our Series 800
RISC product family of workstations and multi-user systems.  It is true
that older programs will not take advantage of the new PA-RISC 1.1
instructions, which primarily affect floating point and graphic
applications.  Dhrystones, for example, are unaffected; SPECmarks are
improved by 20%-30% by recompiling.

Of course, since the Series 700 uses the same HP-UX operating system
as the Series 800, recompiling is simple and fast (as long as you have
source).  If you cannot recompile, your application will still run
faster than it would on any other workstation available today.

						--Linley Gwennap
						  Hewlett-Packard