Prime95 on Linux: The Complete mprime Guide
Quick facts: On Linux, Prime95 30.19 build 20 is not a graphical program. The same code ships as a command-line program called mprime in the official linux64 package, p95v3019b20.linux64.tar.gz (5,912,959 bytes, SHA-256 listed on the download page). There is no Linux GUI to install. You extract the archive to a writable folder, run ./mprime -m to open the menu, and control workers, PrimeNet communication, and the Torture Test entirely from the terminal.
Download and verify the Linux package
Get the package from the download page or through the official direct link at go/prime95-linux64-official, which points to mersenne.org. The download page lists the verified SHA-256 for the linux64 package, so you can run a checksum command in the terminal and compare the output before extracting anything. That habit matters more on Linux because you will run the binary directly from the extracted folder; there is no installer signature step in between. Save the archive somewhere sensible, such as your home folder, rather than a system directory you need elevated permissions to write to.
Extract to a writable working folder
Create a dedicated folder, move the archive into it, and extract it there. mprime writes its configuration, work files, and logs in its working directory, including prime.txt and results files, so the folder must stay writable by your normal user account. Do not extract into a protected system path and then fight permission errors. After extraction you should see the mprime binary together with library files shipped in the package and the familiar text documents, including readme.txt and stress.txt. If the binary does not start, check that you are in the correct folder and that the file is marked executable, and consult the readme’s Linux instructions about the bundled libraries. Run mprime as your regular user; a stress test does not need root.
Start mprime and use the menu
From a terminal in the extracted folder, run:
./mprime -m
The -m flag opens the main menu. From there you can configure whether the machine joins GIMPS through PrimeNet or is used only for testing, set worker counts, and reach the Torture Test. First-time prompts ask about joining GIMPS; if your only goal is stability testing, choose the stress-testing path and skip work assignment, mirroring the Just Stress Testing choice in the Windows program. Menu choices are numbered, and the program saves your answers to prime.txt in the same folder. Because everything is text, mprime works well over SSH on a headless machine, which is one reason Linux builders favour it for overnight runs. Keep the terminal session alive for the run, or use your usual terminal multiplexer so an SSH disconnect does not end the test.
Running the Torture Test on Linux
Inside the menu, open the Torture Test option and choose a preset. The presets mean the same thing as on Windows: Smallest FFTs test the L1 and L2 caches with high power and heat; Small FFTs test L1, L2 and L3 caches with maximum power, heat and CPU stress; Large FFTs stress the memory controller and RAM; Blend, the default, tests all of the above. Since version 29.8 the FFT sizes are selected automatically from cache size, so do not copy fixed size ranges from old guides. The duration guidance is also the same official guidance from stress.txt: 6 to 24 hours for a thorough check, with unstable machines often failing within minutes, and 10 to 15 minute runs reserved for quick steps while tuning. While the test runs, monitor temperatures with your distribution’s usual sensor tools in a second terminal. mprime itself focuses on the computation check; it is not a temperature dashboard.
Files, stopping, and reading the outcome
To stop, use the menu’s stop option or interrupt the program cleanly, then read the result files in the working folder before you change settings. results output records completed tests and error messages, including which worker stopped. If a worker reports a rounding error or a hardware failure message, treat it the same way as on Windows: the computation did not match the known correct result, so suspect the overclock, memory settings, or cooling before suspecting the software. The detailed reading method is in the results interpretation guide linked below. Because prime.txt lives beside the binary, backing up a known-good Linux setup is as simple as copying the whole folder, which also makes mprime naturally portable between similar machines.
Keeping a Linux test folder tidy
Because mprime keeps everything in one folder, a little housekeeping makes long-term testing far clearer. Keep the original verified archive separate from the working folder. After each significant run, copy the results output into a dated subfolder or rename it with the machine name and date, and keep a short note with the preset, duration, and any settings you changed in prime.txt. If you test several machines from the same home directory structure, use one clearly named folder per machine rather than reusing a single mprime folder for all of them, because prime.txt carries worker and menu choices from the previous system. A tidy folder turns a stopping worker from a confusing terminal memory into a record you can compare against the next run, which is the whole point of a checked computation test.
Differences from Windows to remember
There is no system tray icon, no graphical worker windows, and no point-and-click Options menu; every equivalent action is a menu entry or a prime.txt value. Scheduling also differs: if you want mprime to start with the machine for GIMPS work, that is a service or startup configuration you create yourself, separate from a one-off stress test. For a pure stability check, manual menu runs are clearer because you see the start time, preset, and any error directly. Finally, remember that Prime95 and mprime stress CPU and RAM; they do not test a Linux machine’s graphics stack, disks, or network, however long they run.
Next steps
See the platform overview on the platforms page, the Windows workflow in How to Use Prime95, and the full index in the tutorials hub.