From: jim bell <jimbell@pacifier.com>
Date: Thu, 1 Aug 1996 03:49:27 +0800
To: cypherpunks@toad.com
Subject: Re:FPGAs and Heat (Re: Paranoid Musings)
Message-ID: <199607311609.JAA16248@mail.pacifier.com>
MIME-Version: 1.0
Content-Type: text/plain


At 02:14 AM 7/31/96 -0800, Jim McCoy wrote:

>The interconnection problem has also been solved in this chip series. [A
>long-standing problem with FPGAs is that there were generally a limited
>amount of "wires" running between the logic elements and thus a lot of cells
>were wasted because there were no interconnections left, I/O to the outside
>world was also a problem.]  The chip has a really cool interconnection method
>which allows a much more efficient use of the chip real estate and which
>makes the entire chip directly addresable (like regular RAM) through an
>on-chip interface module.  Given the relatively compact design in Ian and
>Dave's paper and the new chips one might even fit two or four cracking
>engines on a single FPGA.

However, I think it very unlikely that an organization like the NSA would 
bother with an FPGA to do a cracking engine.  FPGA's have substantial 
limitations, as you alluded to above, due to the need to make them "general 
purpose."  A non-field programmable Gate Array, a hard-wired chip, would 
tend to optimize the interconnections on chip including minimizing the 
delays, but not incur the full-custom costs such as the penalty for low volume.

Jim Bell
jimbell@pacifier.com