From:David Harvey 
To: Arthur Gaer 
Cc: William A. Stein 
Subject: Re: Lots o'Mem
Date: Fri, 9 Apr 2004 19:11:30 -0400
Hi Arthur,

The problem with the swap space is that my code references memory all 
over the place, and from my experience on my 256MB laptop, if it starts 
swapping it will just collapse in a thrashing heap. My main priority is 
to ensure that I don't interfere with any of the other users on the 
machine (for example Stephanie has been running a few processes for a 
while there), so I don't want to force them to start swapping either.

In case you were wondering what I am doing... for a few months I have 
been studying a type of chromatic polynomial defined for cubic graphs. 
In general the time required to compute this polynomial is exponential 
in the number of vertices; for PLANAR cubic graphs I have a faster 
algorithm, but there's a memory tradeoff. Hence the 14GB. My code 
basically cooks up a large random planar graph (today's had 300 
vertices) and computes the associated polynomial. There are certain 
features of the coefficients of the polynomial which may or may not 
persist for larger graphs, and that's what I'm trying to find out.

It really is fantastic to have that kind of memory around. It's quite 
beyond my capacity to imagine 100 billion bits, but there it is.

Thanks

David