Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!seismo!ll-xn!ames!sdcsvax!jww
From: jww@sdcsvax.UCSD.EDU (Joel West)
Newsgroups: comp.sys.mac
Subject: Re: Mac II and SANE...
Message-ID: <3464@sdcsvax.UCSD.EDU>
Date: Wed, 15-Jul-87 21:59:32 EDT
Article-I.D.: sdcsvax.3464
Posted: Wed Jul 15 21:59:32 1987
Date-Received: Sat, 18-Jul-87 03:26:07 EDT
References: <10882@decwrl.DEC.COM>
Organization: Palomar Software, Inc., Vista, CA
Lines: 17
Summary: Some SANity

You don't say what you're benchmarking; arithmetic, trig,
logs, whatever?

SANE can use the 881 for arithmetic, but the 881 has a rounding
error in the last digit (according to Apple) for the
trancendentals.  For accuracy's sake, Apple recommends you use
SANE rather than the 881, and clearly the Mac II SANE strives
for the accuracy of the 128K ROM version rather than the speed
of the 881.

Don't forget that a sizable amount of the cost
of SANE is trap and package dispatching; for that, the linear
speedup of 68000 instructions is the payoff.  That's why going
straight to the 881 is 20-100x as fast as a Plus.
-- 
	Joel West,  Palomar Software, Inc. (c/o UCSD)
	{ucbvax,ihnp4}!sdcsvax!jww or jww@sdcsvax.ucsd.edu