Great Internet Mersenne Prime Search and GIMPS for Windows PC

Prime95

Prime95 30.3 Build 6 (64-bit)

  -  9.88 MB  -  Freeware

Sometimes latest versions of the software can cause issues when installed on older devices or devices running an older version of the operating system.

Software makers usually fix these issues but it can take them some time. What you can do in the meantime is to download and install an older version of Prime95 30.3 Build 6 (64-bit).


For those interested in downloading the most recent release of Prime95 or reading our review, simply click here.


All old versions distributed on our website are completely virus-free and available for download at no cost.


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  • Prime95 30.3 Build 6 (64-bit) Screenshots

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    Prime95 30.3 Build 6 (64-bit) Screenshot 1
  • Prime95 30.3 Build 6 (64-bit) Screenshot 2
  • Prime95 30.3 Build 6 (64-bit) Screenshot 3
  • Prime95 30.3 Build 6 (64-bit) Screenshot 4

What's new in this version:

- PRP proofs. This allows GIMPS to double-check a PRP test at less than 1% of the cost of a full PRP test
- PRP proofs require lots of temporary disk space. See readme.txt for details
- PRP proofs require uploading a large proof file. See readme.txt for details
- PRP proof verifications require downloading a modest verification file. See readme.txt for details
- Proofs automatically uploaded to server in 30.2
- First time LL, World-record LL, 100M-digit LL work preference is deprecated
- New resource limits menu choice and dialog box. Consult readme.txt before making changes to these settings
- Some options previously in Test/Worker Windows and Options/CPU are moved to the resources dialog box
- LL-DC and PRP-DC combined into a single work preference
- Warning raised if temporary disk space is less than 1.5GB -- you may not get first time prime tests
- The P-1 probability calculator has been improved. This change results in a lower optimal B1 value and higher optimal B2 value