Networking Prime95:
PrimeNet Server for NT 4.0
Parallel Technology for the Great Internet Mersenne Prime Search
Updated 01/06/98

PrimeNet 3.0 Features

PrimeNet 2.6 Passes the 100 Site Mark!


PrimeNet 2.6 Demographics*
Now 101 installed server sites!

31 U.S. ISP users (,
20 unspecified domain type sites
18 international ISP users
... (4:de,3:nl,2:no,1:au,be,ca,ch,cz,fr,it,th,uk)
10 commercial businesses
6 .edu universities
1 .mil U.S. military base
1 .org dialup ISP

*as of 10/22/97 - download server names
excluding repeats for updates, Parallel Test
Challenge sites and source code built sites
(221 run-time licenses downloaded)

1 out of every 5 web visitors
downloads PrimeNet software

20% of you
have something in common...

Easy, mass Mersenne test production!




PrimeNet is about more easily running many concurrent Mersenne number tests for the Great Internet Mersenne Prime Search project. The free software, below, can let you access and use the Internet PrimeNet Server, or operate your own testing network.


If you are interested only in testing Mersenne numbers, you can skip directly to the PrimeNet Parallel Test Challenge, which is a complete 'kit' for starting a test setup on the Internet. We provide the server and manage the testing for you!

If you are already running Prime95.exe or NTPrime.exe 15.2, testing exponents for the GIMPS project, you can also connect to the Internet Prime Server for test assignments and results collection.

PrimeNet has two parts: the PrimeNet server, and the PrimeNet client DLL. Both are currently available for Windows NT and Windows 95/98. PrimeNet 2.6 Server does not support Prime95 15.1 or 15.2 clients.

The software is free, including the source code, so long as you do not sell it, or sell parts of it, or use it as part of a sold product or service. If you know anything about writing software, you will probably notice the source code reflects several programming no-nos. I'm quite out of practice, and PrimeNet is just for fun anyway.

PrimeNet's server software coordinates parallel Mersenne prime tests using any of George Woltman's Mersenne test programs (14.4 and later) with the PrimeNet.dll interface on the Internet or an NT network. Use of PrimeNet is assumed to be in conjunction with the Great Internet Mersenne Prime Search project. The more familiar you are with Prime95.exe, the easier it will be for you to network several of them using PrimeNet. If you will be setting up PrimeNet so that the client and server are in different NT domains, some NT security admin expertise might be important.

This server implementation works on NT 4.0 or 3.51 servers or workstations and Windows 95 workstations (in console mode) for:

The client can be another NT Server, NT workstation or Windows 95. I have not tried the RPC with a non-Win32 client, but clearly non-Win32 client support is desirable.

Here's what Prime95 needs for a collection of parallel test systems before and after installing PrimeNet:

each of n machines has:
each of n machines has:
network server has:

control console
(often at the server) has:


*when factoring




*when factoring








There are a few changes in which files are used by Prime95 when using PrimeNet:

The PrimeNet 2.6 database is 64 bits per record. You periodically merge updates from the 32-bit databases that George Woltman distributes into this database using the command console.

Protocol and server identification is done on the PrimeNet client side configuration. I've tested the TCP/IP configuration on an NT Internet server but I don't know how loose the firewall must be. The RPC dynamically assigns a port number greater than 1024, so when using proxys it must support the 'default' port to let the server assign it.

Special thanks to:

Good luck and happy hunting. Send me bugs, suggestions, setup problems & ideas.

- Scott Kurowski

Prime95 15.2 Beta 3

Today, a thousand accounts are testing well over 3000 Prime95 exponent assignments. using PrimeNet 3.0 as the official Internet PrimeNet Server for the Great Internet Mersenne Prime Search!

IPS is jointly operated by myself and George Woltman, who issues assignment test ranges and collects test results received by the server. The IPS server produces an automatic IPS Top Producers Awards report, cumulative for exponent test assignments received by IPS. George separately credits these on his GIMPS Top Producer Awards.

On 3 January, general availability of Prime95 beta 3 version 15.2 was announced, specifically designed for use with the Internet PrimeNet Server (IPS), running PrimeNet Server 3.0. The beta software can be downloaded directly from

The Internet PrimeNet Server (IPS) was upgraded to PrimeNet 3.0 on 18 October, safely transitioning over 150 Prime95 14.4/PrimeNet 2.6 Parallel Test Challenge clients. Fine-tuning and testing continued for the next several weeks, while hundreds of GIMPS testers moved to the server with Prime95 15 beta 1, and later beta 2, 15.1. Now Prime95 15.2 opens proxy and firewall support as well as putting more Mersenne testing control and tracking into your hands.

Several new features will be rounded out incrementally over the course of the first few PrimeNet 3.0 and Prime95 15.0 releases.

PrimeNet 2.6 Software

When installing updated versions of PrimeNet over earlier versions please check the Installing Updates to Earlier Versions section to see if there are special steps necessary to update the software. Free e-mail support help, as well as known problems or bugs in earlier versions of PrimeNet, are described in the Tips & Help section.

Download Free Software:

PrimeNet Freeware License Agreement: PrimeNet software and source code are licensed for free use if you do not sell it, sell parts of it, or include it as a part of a sold product or use it for a sold service. PrimeNet source code, intact or modified, is licensed for use solely with the Great Internet Mersenne Prime Search project. No warranties or liabilities are assumed, offered or implied. Use of PrimeNet software and/or source code constitutes implicit agreement with the terms of this freeware license.

What's in PrimeNet 2.6
Updated 10/26/97

The last major enhancement to PrimeNet 2.6 will be it's hierarchial server support. This will enable PrimeNet 2.6 servers to be a client of a PrimeNet 3.0 server, which will assign block exponent test ranges and collect block test results.

PrimeNet 2.6 currently contains these incrementally delivered features:

PrimeNet 3.0 pre-release build Features

The latest PrimeNet software is designed specifically for Internet-based Mersenne number testing.

Unfinished Work List
Updated 9/23/97

There are several areas where someone could contribute to the project:

  1. Adding an install script or wizard.

  2. Check into non-Win32 RPC for UNIX prime testing clients. The source code includes the Interface Definition Language file rpcsvc.idl for the RPC but if this is not enough I can probably offer some help.

  3. General testing of new versions PrimeNet and Primecom.exe server control console application.


*Windows NT and Windows 95 are trademarks of Microsoft, Inc.

> 6 April 1997.