Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!cbmvax!daveh
From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: Upgrading A3000s
Message-ID: <14546@cbmvax.commodore.com>
Date: 19 Sep 90 21:39:23 GMT
References: <4497@crash.cts.com>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Organization: Commodore, West Chester, PA
Lines: 24

In article <4497@crash.cts.com> seanc@pro-party.cts.com (Sean Cunningham) writes:

>I'm aware that the two machines have different BUSTER chips...but would there
>be a difference in throughput across ZORRO ]I[ on the two machines (ie:
>A3000-25/50 = 20MB/sec...while...A3000-16/50 = 12MB/sec (is this due to
>different CPUs?))?

Actually, they have the same BUSTER chip.  The bus speed difference is the
result of clocking BUSTER at 25MHz vs. 16MHz.  A Coprocessor slot device
can run the entire A3000, except for 68030/68882, at 25MHz by supplying its
own clocks, even on a 16MHz system.  The only had difference would be for
a Coprocessor slot device that intends to keep the on-board 68030 active --
obviously such a device can't run the motherboard at 25MHz when a 16MHz
68030 is using it.  I would imagine the basic 68040 boards simply take over
from the 68030, much as the 68030 boards on the A2000 do.  But it's very
possible to run both simultaneously, so you won't really know what's what
until the 68040 boards ship.

>  RealWorld: Sean Cunningham                   |   a sect. "

-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
      Get that coffee outta my face, put a Margarita in its place!