[Help-glpk] [Fwd: memory]

[Andrew Makhorin]

-------- Forwarded Message --------
From: Ronald Wolthoff <address@hidden>
To: address@hidden
Subject: memory
Date: Thu, 24 Nov 2011 09:44:57 -0500

Hello,

I'm using GLPK in combination with CMPL and I encounter some issues with 
the time required for preprocessing. My problem has 2N^2 rows and 2N^4 
columns (real variables, less than 1% non-zeros). When I run the problem 
for N=15 (450 rows, 101250 columns), the preprocessing takes 
approximately 1 minute and the solver 3 seconds, which is great. When I 
use N=30 instead (1800 rows, 1,620,000 columns) , the solving time goes 
up to a few minutes, which is still great, but the preprocessing time 
explodes to something like 9 hours. Although the problem is fairly 
large, this increase seems stronger than expected. Is there a way I 
could reduce the preprocessing time, e.g. by allocating more memory to 
the program?

Many thanks,

Ronald