Path: utzoo!attcan!uunet!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Is 14.32MHz too fast for my expansion RAM?
Message-ID: <4572@cbmvax.UUCP>
Date: 25 Aug 88 16:32:22 GMT
References: <3127@sdsu.UUCP>
Distribution: comp.sys.amiga.tech
Organization: Commodore Technology, West Chester, PA
Lines: 31

in article <3127@sdsu.UUCP>, larryr@sdsu.UUCP (Larry Riedel) says:
> Keywords: volatile

> I am thinking about getting that 14MHz 68000 thing from CMI, but I am
> wondering if the extra clock speed will be wasted.  I have one of those
> Micron 2MB boards, and I don't know how fast the memory is.  Will the
> fast processor just be hurry-up-and-waiting?

All of the Amiga speedup boards run the Expansion Bus memory at it's
normal speed.  They do speed the system up, but they only run faster
in the following cases:

	- Internal CPU operation
	- Cache hit
	- Access to special fast memory

If you're using a Commodore-Amiga A2620 or a CSA or Hurricane board with
their fast memory options, you get all three benefits.  A plain fast
68000 with no on-board memory designed specifically for it will only
get the first benefit.  So you'll get some additional speed, but it's
had to say just how much.  With a decent amount of memory that'll keep
up with that 68000 (it would go somewhere on the 68000's board), you
might approach a factor of 2 speedup (you'll never really get there,
since you have to access CHIP ram or I/O registers at least some of
the time).

> Larry         ...!ucsd!sdsu!larryr
-- 
Dave Haynie  "The 32 Bit Guy"     Commodore-Amiga  "The Crew That Never Rests"
   {ihnp4|uunet|rutgers}!cbmvax!daveh      PLINK: D-DAVE H     BIX: hazy
		"I can't relax, 'cause I'm a Boinger!"