Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!oliveb!amiga!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: Whay has commodore droped the transputer
Message-ID: <4613@cbmvax.UUCP>
Date: 31 Aug 88 16:34:12 GMT
References: <88Aug29.235507edt.661@neat.ai.toronto.edu>
Organization: Commodore Technology, West Chester, PA
Lines: 31

in article <88Aug29.235507edt.661@neat.ai.toronto.edu>, yann@ai.toronto.edu (Yann le Cun) says:
> 
>> the transputer might have become if fielded five years ago.  Today
>> (with 20 MIP RISC processors) it just isn't worth a second glance.

> but the transputer *IS* a *cheap* 20 MIPS RISC processor, well, make 
> that 10 MIPS and put two of them.

> Yann le Cun                            yann@ai.toronto.edu

In any REAL Transputer environment, it comes out looking more like a 2-3
MIPS machine at best.  The Transputer is RISCy, in that it uses some
RISC concepts, but it also misses alot of them.  It's got that nice 4k
of very fast RAM on chip, but it's not cache RAM.  So you pay a big
penalty for going off-chip to get memory and the off-chip memory interface 
is real slow.  And from a programming point of view the Transputer is a weird
stack machine that requires lots of instructions to do things and doesn't
give you real registers.  Add it all up and no Transupter gives you a 
reasonable bang per buck.  Even in multi-Transputer systems you may still
be in trouble.  A 68030 loosely coupled multiprocessing system would require
1/2 less than half the number of CPUs that a similar Transputer system would.
I could build a killer link interface external to the '030 for the money I'd
save there.  And I'd get memory mapping and protection as well, which you
don't get at all on the Transputer.



-- 
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!"