Subject: Re: cache
To: None <jms@tardis.Tymnet.COM>
From: None <bsieker@TechFak.Uni-Bielefeld.DE>
List: amiga
Date: 03/26/1996 13:44:05
> Date: Mon, 25 Mar 96 15:43:31 PST
> From: jms@tardis.Tymnet.COM (Joe Smith)
> > From: (YU SONG)
> > To: amiga@NetBSD.ORG
> > Subject: cache
> > 
> > However, as I was 
> > told before that the memory access in stock Amiga ( A4000 in my case )
> > is quite slow.
> You have been misinformed.  Memory access in the Amiga between the CPU and
> fast RAM is quite fast.  So fast, that adding an L2 cache will not make it
> any faster.

No, he's right. (Motherboard-) FastRAM access in the Amiga 4000/040
(with tha Commodore A3640 card) is very slow! Only up to about 12

FastRAM access with any 68030 card (like the factory installed in
A4000/EC030 or a Blizzard '4030') is much faster. Quite the same goes
for the A3000, FastRAM access with the motherboard-installed 68030
goes up to about 17 MB/s; with the A3640 installed it is back to
12 MB/s.

FastRAM access for on-board RAM on CPU boards like WarpEngine or
Cyberstorm is fast and can reach peak values of about 50 MB/s.

(all measurements have been made with "bustest" by Michael van Elst)


Bernd Sieker \\ email:
IRC: Pink    \\ HAM-Radio: DG6YHI (@DB0EAM.#NRW.DEU.EU)
"Bruno Heinz Jaja, unlike Strawinsky, has never been guilty of
composing harmony in all his life!"