Prime95 for Mac

Prime95 for Mac is a small and easy to use free software that allows you to find Mersenne Prime numbers designed for overclockers. This software describes what you will need to participate in GIMPS and how it works on your computer. This page is aimed at people with Intel-compatible personal computers, although in many cases it is possible for UNIX and Mac users to participate as well.

Getting Started on GIMPS

1. Create a new user account (Optional / Recommended)

Your account login is the "container" that holds your preferences, your computer and work assignments info, and your productivity statistics. There is no limit to the number of computers you can have in your account.

Registration is optional but recommended. An account is required to check your account details, computer status, and performance statistics and to assign computers to your user ID. You also need an account if you joined GIMPS before November 2008 so you can link your old PrimeNet V4.0 account and transfer your CPU work credit.

2. Download Prime95 or similar software onto your computer(s)

The How it Works page answers many questions you may have before downloading the software. The software has been upgraded through the years, since 1996, to work successfully on hundreds of thousands of home, office, school, and business computers.  The software program uses only the leftover idle processor cycles unused by other programs and has been designed to take advantage of the power of the latest processor features. Be sure to obtain permission from the computer's owner if it's not yours!

3. Start the program, optionally entering your user account information if you created one

The program will save your account information when you enter your user and password and starts working immediately! You can see each computer added to your account using your Computer CPU Details page, as well as it's latest reported status, current assignments, and a list of results.

Once you have your computers added to your account and running work assignments, you can:

• Customize your account settings
• Set an optional public name used for statistical reports and milestones
• Optionally join a team to pool your stats and workload
• Review your account status, performance, and ranking
• Link your personal web site to your stats entries
• Remotely manage your computers from where you can:
• Change computer names for tracking
• Set computer-specific work assignment preferences
• Review detailed operating stats and facts
• Review your completed work assignments, stats, and facts
• Be a team leader: Create and manage a team!
• And more!

GIMPS requires a modern Mac that is on most of the time. The program runs at the lowest possible priority. You should not see any impact on your system's performance. The program will use about 32MB of memory and about 50MB of disk space. WARNING: Running the program continuously will use about 40 watts of additional power, about the same as an energy-saving compact fluorescent lamp - your electric bill will go up just a little bit. Credit for this prime goes not only to Patrick Laroche for running the Prime95 for macOS software, Woltman for writing the software, Blosser for keeping the Primenet server running smoothly, and the thousands of GIMPS volunteers that sifted through millions of non-prime candidates.

Please consult the readme.txt file for possible answers. You can also search for an answer, or ask for help in the GIMPS forums. Otherwise, you will need to address your question to one of the two people who wrote the program. Networking and server problems should be sent to Scott Kurowski. Such problems include errors contacting the server, problems with assignments or users, and errors on the server's statistics page. All other problems and questions should be sent to George Woltman, but please consult the forums first.

Also Available: Download Prime95 for Windows