Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!sdd.hp.com!uakari.primate.wisc.edu!zaphod.mps.ohio-state.edu!rpi!batcomputer!riley
From: riley@batcomputer.tn.cornell.edu (Daniel S. Riley)
Newsgroups: comp.sys.atari.st
Subject: Re: Atari TT 030 Launched!
Keywords: Atari TT
Message-ID: <10373@batcomputer.tn.cornell.edu>
Date: 6 Jun 90 16:39:24 GMT
References: <1990Jun5.143231.4977@watserv1.waterloo.edu> <13266@wpi.wpi.edu> <81214@tut.cis.ohio-state.edu> <1990Jun6.044350.20403@cbnewsh.att.com>
Reply-To: riley@tcgould.tn.cornell.edu (Daniel S. Riley)
Organization: Cornell Theory Center, Cornell University, Ithaca NY
Lines: 27

In article <1990Jun6.044350.20403@cbnewsh.att.com> wolf@cbnewsh.att.com (thomas.wolf) writes:
>Could you contain your mindless ravings?  The poster mentioned that 1/3
>increases were with non-030 applications (ie those written for the MC68000).
>I seriously doubt your claim that a ~9-fold increase was achieved on the A2500
>WITHOUT optimizing the code towards a 68030.

That wasn't mindless ravings.  Seriously, that 1/3 number confuses me--it
should be lots higher.  Going from a 16 bit to 32 bit machine and doubling
the clock speed (8 MHz to 16 MHz) should give you at least a factor of 4,
and then some because the '30 takes fewer clocks to do some things.
There aren't that many new opcodes or addressing modes for the '30, so
the speed increase from recompiling for a '30 should be relatively small
(unless you're doing lots of floating point, in which case the coprocessor
gives you a whopping big factor).

Serious question--why is it so small?  Is that 1/3 correct?  Do they have to
do something ugly for backward compatibility, like turn off all the caches
and force the '30 to do 16-bit accesses unless the program says that it is
'30 compatible?

Finally, the TT probably should be compared to the 16 MHz A3000, since the
TT is 16 MHz.  List US price for a 16 MHz A3000 with 2 Meg RAM, 40 Meg
hard disk, 68881, and no monitor, is $3300 (US).  25 MHz A3000 is $4000 US, 
which is probably what the original poster was thinking of.

-Dan Riley (riley@tcgould.tn.cornell.edu, cornell!batcomputer!riley)
-Wilson Lab, Cornell University