Hi

Thanks for the feedback. I'm sorry that I reply so late but I had some
exams last week.

Organisation of p-1 factoring:

The factoring is mainly done by George Woltman and Alex Kruppa.
George ran p-1 on the exponents 20000 to 110000 using B1=1M; B2=40M, and
Alex did the p-1 from 150000 to 600000 using B1=100k; B2=4M (still in
progress). Both have kept the save files.
George told me that Alex is starting at 110000 and Alex reported me
150000. It seems as if a little misunderstanding caused a gap between
these two values.

At the moment the situation is quite simple.
If a lot of other people intend to do further p-1 factoring, Brian
Beesley is willing collect these information and put onto his ftp
server.
I think that is not necessary at the moment to store the save files
online. But a database with the limits makes sense. Everyone who wants
to do some further p-1 factoring can request the files from Alex and
George then.

> However, it must be pointed out that at some point you are better off
> switching to ECM rather than expanding the P-1 bounds. I'm not sure
> what that point is.
(George)

When we take some exponents and spend as much time in the further p-1
factoring as in the ECM on them , we can find out which approach brings
more factors.
George told me that 1 B1=250k ECM curve is worth 5 curves using a 50k
bound. If it is similar in p-1 factoring, further p-1 factoring will be
better than ECM, but I don't think so due to the internal structure of
the factors found by p-1.

Parallel use of p-1 and trial factoring:

When we change between these two methods during the factoring, we can
optimise the average time to find a factor. It makes no sense to split
up the assignment in more than two pieces (p-1 and trial).
An idea is to make three types of assignments:
1. trial factoring for computers which have not much memory.
2. p-1 factoring for which have a lot of memory.
3. complete factoring (p-1 and trial) for the average computers which
run all the time. These computers change between factoring when it is in
use and p-1 during the night.

Regards
Reto



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