Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!uunet!mcvax!ukc!acorn!moncam!paul
From: paul@moncam.co.uk (Paul Hudson)
Newsgroups: comp.arch
Subject: Re: Criteria for comparing RISC processors
Summary: ARM is good, but not that good.
Keywords: RISC, Acorn, ARM
Message-ID: <132@marvin.moncam.co.uk>
Date: 20 Apr 89 15:54:53 GMT
References: <2368@ogccse.ogc.edu> <596@eutrc3.UUCP>
Organization: Monotype ADG, Cambridge, UK
Lines: 40

In article <596@eutrc3.UUCP>, rcbaps@eutrc3.UUCP (Pieter Schoenmakers) writes:
> In article <2368@ogccse.ogc.edu> johnr@ogccse.ogc.edu (John Roberts) writes:
> >I'm interested in evaluation of the current crop of RISC processors based
> >on some common criteria.  Here's the list of RISC processors I know about
> >(feel free to add more):
> >
> >[...]
> >	VLSI Technology VL86C010
> >[...]
> Just to mention my favourite CPU: The Acorn RISC Machine (ARM), aka VL86C010.
> Data for the ARM-2 (Used in the Acorn Unix Workstation):

Problems: Max 4Mb memory with current memory controller.
	  32 Kbytes page size.
	  Poor 16 bit support (a problem with some peripherals).
	  No DMA support.
	  High-resolution screens steal a lot of bandwidth.
	  No delayed branch.


Goodies:  Uses cheap memory well.
	  Is v. cheap
	  Nice instruction set (although few instructions, it's remarkablly
	  flexible. Pre-increment by 17? Post-increment by 134? No problem.
	  All maths ops are 3 operand, and one operand can be fed to a barrel
	  shifter. This is a *big win*.).

Conclusion.
	  In the right application, unbeatable. Not my choice for a workstattion.

Disclaimer: I used to work for Acorn, and have writtern (the back end of) a compiler
	for the beast. Thus the above may be disillusionmemnt.

Paul Hudson 

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