Hi everyone,
Thanks to all that replied to my earlier email. Here I'll summarize,
in no particular order, the important points in the replies
It seems the majority of responders feel the prudent decision is
for prime95 to use the minimum amount of memory by default. I will
have prime95 default to 8MB of memory in the Options/CPU dialog box.
If the user leaves this value unchanged I'll pop up a message box
explaining why he might want to increase the value. I should
also display this message when a user upgrades from v19 to v20.
No one suggested a sure-fire method for making sure prime95
is not causing thrashing. Some did suggest Windows calls that will yield
useful data - but were vague on how these statistics are to be
interpreted. I imagine there isn't a single solution that will satisfy
every users setup and thus it is best for prime95 to let the end-user
make the decision for his machine.
Stage 1 of P-1 stage 1 uses the same amount of memory as
a LL test. Thus, even those users that do not give prime95 more memory
to work with will do a little P-1 factoring. For example, exponent 10,000,139
P-1 will go to B1=130000 with a 2.02% chance of finding a factor (cost is 1.87%
of an LL test). If given 48MB of memory, prime95 uses B1=110000 and
B2=1815000 with a 4.15% chance of finding a factor (cost is 3.17% of an LL
test).
If you give prime95 48MB of memory but only from 11PM to 7AM, then if
stage 2 needs to run between 7AM and 11PM prime95 will instead begin work on
the next item in the worktodo.ini file or begin the LL test on the
assumption you
are unlikely to find a factor anyway.
P-1 factoring will be a separate work assignment when Scott has the
time to make the necessary changes on the PrimeNet server. The initial
release of version 20 will probably not have separate assignments.
Some suggested prime95 grow and shrink memory usage based on
paging rates, etc. Apparently, I did not explain the stage 2 requirements very
well. Before embarking on stage 2, prime95 needs to know how much memory
it can use. Once stage 2 has begun, prime95 cannot grow or shrink its
memory consumption.
Best regards,
George
_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
