> < ^ Date: Fri, 04 Jun 1999 10:06:32 +0100
^ From: A. C. Aitchison <A.C.Aitchison@dpmms.cam.ac.uk >
< ^ Subject: Re: Unit groups of order 2^31 in Sisyphos

On Thu, 3 Jun 1999, Alexander B. Konovalov wrote:
> does anybody know what hardware resources are necessary to compute
> normalized units group of group algebra of group of order 32 over GF(2),
> using the function NormalizedUnitsGroupRing ?
> I have tried to do this under Linux on Pentium-166 with RAM 32 Mb and
> swap partition of 50 Mb, and even with "-30m" parameter this calculation
> was terminated with message like "cannot allocate workspace" after
> about 5 minutes of work.

I don't know how much space it will take, but give those symptoms it
sounds as if it needs some space for each element. You say there are 2^31
elements, so *at one bit per element* you will need 2gigabits, or 256Mb.
It may use more than one bit per element, in which case you will need
a multiple of 256Mb.

Perhaps someone else on the list can tell you whether the calculation
can be done without using a bit for each element.

Note that many versions of linux need reconfiguring to use a swap
partition >128Mb (although they are happy with multiple swap partitions).

Dr. Andrew C. Aitchison Computer Officer, DPMMS, Cambridge
A.C.Aitchison@dpmms.cam.ac.uk http://www.dpmms.cam.ac.uk/~werdna

> < [top]