Welcome to the Great Internet Mersenne Prime Search!
To use this program you must agree to the terms and conditions,
prize rules, etc. at http://mersenne.org/legal/
In case you ever forget, the GIMPS web site is at http://mersenne.org
My email address is woltman@alum.mit.edu. For networking questions,
contact Scott Kurowski at primenet@mersenne.org.
FILE LIST
---------
readme.txt This file.
prime95.exe The program to factor and run Lucas-Lehmer tests on
Mersenne numbers.
whatsnew.txt A list of new features in prime95.exe.
stress.txt A discussion of issues relating to stress testing a computer.
undoc.txt A list of undocumented and unsupported features.
prime.txt A file containing your preferences. The menu choices
and dialog boxes are used to change your preferences.
local.txt Like prime.txt, this file contains more preferences.
The reason there are two files is discussed later.
worktodo.txt A list of exponents the program will be factoring
and/or Lucas-Lehmer testing.
results.txt Prime95.exe writes its results to this file.
prime.log A text file listing all messages that have been sent
to the PrimeNet server.
prime.spl A binary file of messages that have not yet been sent to
the PrimeNet server.
pNNNNNNN,pNNNNNNN.buN Intermediate files produced by prime95.exe to resume
computation where it left off.
eNNNNNNN,eNNNNNNN.buN Intermediate files produced during ECM factoring.
fNNNNNNN,fNNNNNNN.buN Intermediate files produced during trial factoring.
mNNNNNNN,mNNNNNNN.buN Intermediate files produced during P-1 factoring.
WHAT IS THIS PROGRAM?
---------------------
This program is used to find Mersenne Prime numbers. See
http://www.utm.edu/research/primes/mersenne.shtml for a good
description of Mersenne primes. Mersenne numbers can be proved
composite (not prime) by either finding a factor or by running
a Lucas-Lehmer primality test.
INSTRUCTIONS
------------
There are two ways to use this program. The automatic way uses
a central server, which we call the PrimeNet server, to get work to do
and report your results. You do not need a permanent connection to the Internet.
The second method is the manual method. It requires a little more work
and monitoring. I recommend this for computers with no Internet access
or with some kind of firewall problem that prevents the automatic method
from working.
If you are running this program at your place of employment, you must
first GET PERMISSION from your network administrator, boss, or both.
This is especially true if you are installing the software on several machines.
Many companies have policies that prohibit running unauthorized software.
Violating that policy could result in termination and/or prosecution.
INSTRUCTIONS FOR THE AUTOMATIC METHOD
-------------------------------------
1) Download and unzip prime95.zip.
You've probably done this already since you are reading this file.
2) Connect to the Internet. Create an account at http://mersenne.org
3) Run prime95.exe. You will see 4 dialog boxes:
3a) In the welcome dialog box, choose "Join GIMPS!".
3b) In the second dialog box, enter your user id and optional computer name.
If you are using several computers, use the same user ID but a unique computer
name on each machine. An easy-to-remember user ID will be helpful if you
plan to visit the PrimeNet server's web page to view reports on your
progress.
3c) In the third dialog box, fill in roughly how many hours a day you leave
your computer running. Click OK (just close the dialog box on a Mac).
3d) In the fourth dialog box, leave the "Use Primenet..." checkbox
checked. Do not turn this checkbox off even if you disconnect
from the Internet. Check the "Use a dial-up..." checkbox
if you use a modem to connect to the Internet. Note that prime95
will not dial-up to connect to the Internet, rather it waits
for a time when you are already connected to contact the server.
Click OK. Prime95 will now contact the PrimeNet server to get some
work for your computer to do.
4a) If a proxy server is the causing connection troubles, see the
later section on "SETTING UP A PROXY SERVER".
4b) If the program will not connect to the server, then
you will have to use the manual method described below.
5) Disable screen savers or use the "blank screen" screen saver. If this
is not practical, consider raising prime95's priority to 4 or 5.
The "Start at Bootup" menu choice (on by default) will run prime95
every time you boot your computer. The "Start at Bootup" choice
became "Start at Logon" starting with Windows Vista.
MANUAL METHOD INSTRUCTIONS
--------------------------
1) Visit http://mersenne.org/update/ to create a userid for yourself and
http://mersenne.org/manual_assignment/ to get an exponent or two to
work on. Copy these exponents to a file called worktodo.txt.
2) Run prime95.exe. You will see 3 dialog boxes:
2a) In the welcome dialog box, choose "Join GIMPS!".
2b) In the second dialog box, fill in roughly how many hours a day you leave
your computer running. Click OK.
2c) In the third dialog box, uncheck "Use PrimeNet to get work and report
results", click OK.
3) Disable screen savers or use the "blank screen" screen saver. If this
is not practical, consider raising prime95's priority to 4 or 5.
4) When done with your exponents, use the web pages again to send the
file "results.txt" to the PrimeNet server and get more work.
The "Start at Bootup" menu choice (on by default) will run prime95
every time you boot your computer. The "Start at Bootup" choice
became "Start at Logon" starting with Windows Vista.
NOTES
-----
Running prime95 may SIGNIFICANTLY INCREASE YOUR ELECTRIC BILL. The amount
depends on your computer and your local electric rates.
It can take many CPU weeks to test a large Mersenne number. This program
can be safely interrupted by using the ESC key to write intermediate results
to disk. This program also saves intermediate results to disk every 30 minutes
in case there is a power failure.
You can compare your computer's speed with other users by checking the
web page http://mersenne.org/report_benchmarks/. If you are much slower
than comparable machines, utilities such as Task Manager are available
that can find programs that are using CPU cycles.
You can get several reports of your PrimeNet activity at any time
by logging in at http://mersenne.org/.
If you have overclocked your machine, I recommend running the torture
test for a day. The longer you run the torture test the greater the
chance that you will uncover possible problems caused by overheating
or overstressed memory.
Depending on the exponent being tested, the program may decide that it
would be wise to invest some time checking for small factors before
running a Lucas-Lehmer test.
SETTING UP A PROXY SERVER
-------------------------
Choose the "Connection..." button in the Test/Primenet dialog box. Fill in
the proxy information.
SETTING P-1/ECM STAGE 2 MEMORY
------------------------------
Stage 2 of P-1 factoring step prior to running a Lucas-Lehmer test is
slightly more effective if it is given more memory to work with. However,
if you let the program use too much memory then the performance of ALL programs
will suffer. The good news is that 98% of the time the program uses a minimal
amount of memory. In fact, the program will work just fine if you never
let it use more than the minimum.
So how do you intelligently choose the memory settings? Below
are some steps you might take to figure this out:
1) Be conservative. It is better to set the memory too low
than too high. Setting the value too high can cause thrashing which
slows down all programs. Remember, the program will on