Prime95

Prime95 30.7 build 5

  • Assume CERTs will complete before all other work types in computing estimated completion dates. Fixed in build 5.
  • A low-memory situation during stage 2 init of ECM could lead to a crash writing a save file. Fixed in build 5.
  • During stage 2 init, checking for a restart due to a reduction in available memory was infrequent. Fixed in build 5 - might reduce chance of an out-of-memory event.
  • Hyperthreaded torture tests not setting affinity properly for small FFTs. Fixed in build 4.
  • Hyperthreaded in-place torture tests crash for small FFTs. Fixed in build 4.
  • Semi-obscure ECM crash. If an ECM curve needed modular inverses in stage 2 and a subsequent curve needed none (more memory available), then a crash occurred. Fixed in build 4
06.10.2021

Changelog:

1) Better prime pairing in stage 2 of ECM/P-1/P+1. This usually results in slightly better
stage 2 timings or less memory used. Save file formats changed - upgrading to 30.7 while
ECM/P-1/P+1 work is in stage 2 will result in stage 2 being restarted from scratch.

2) P-1 converted to use P+1 style stage 2. From the users perpective there is no difference.
Internally a modular inverse is required at stage 2 init, but there is one multiplication
saved for every D-block processed. For all common P-1 cases, this is a little faster.

3) ECM/P-1/P+1 no longer use a bit map for prime pairs. Instead a compressed pairing map is
created to save memory. For large B2 values this also results in fewer calls to generate
pairing maps. It also makes stage 2 save files smaller.

4) Some minor changes in AVX-512 FFT crossovers. ECM/P-1/P+1 all changed to rollback to the
last save file and switch to a larger FFT size should an excessive roundoff error be
encountered.

5) Support for asymmetric processor architectures such as Intel's Alder Lake.

6) Torture test dialog now asks for number of cores to test along with a "Use hyperthreading"
checkbox. Previously, the dialog box asked for total number of torture threads to execute.

7) Versions 30.4/30.5/30.6 were underestimating the cost of P-1 stage 2 relative to P-1 stage 1.
Expect this version to use lower stage 2 bounds in P-1.
Several bug fixes:
  • Torture tests
  • AVX-512 P+1 on FFT lengths that are a multiple of 7
  • best 36M FFT selection
21.03.2021

Changelog:

1) Faster P-1 stage 2.
2) Faster ECM stage 1 and stage 2.
3) Gwnum library overhauled. Many functions deprecated. Replaced by more
powerful gwmul3. New functions that compute (a+b)*c and (a-b)*c with less
memory accesses. Faster conversion to and from binary.
4) ECM and P-1 can find the best B2 value for the amount of memory prime95
is allowed to use. For ECM, this happens when the worktodo.txt line sets
B2=100*B1 which is the default assignment from the PrimeNet server. For P-1, the
best B2 is chosen when the worktodo.txt line specifies the trial factoring depth.
For example, "Pminus1=1,2,20000003,-1,500000,0,70" chooses the best B2
bound for B1=500000 given that M20000003 has been trial factored to 2^70.


Download links:
Windows 64-bit: https://mersenne.org/ftp_root/gimps/p95v305b2.win64.zip
Linux 64-bit: https://mersenne.org/ftp_root/gimps/...linux64.tar.gz
FreeBSD 64-bit: https://mersenne.org/ftp_root/gimps/...SD11-64.tar.gz
Source: https://mersenne.org/ftp_root/gimps/...5b2.source.zip
Windows 32-bit: https://mersenne.org/ftp_root/gimps/p95v305b2.win32.zip
Linux 32-bit: https://mersenne.org/ftp_root/gimps/...linux32.tar.gz
Windows Service 64-bit: https://mersenne.org/ftp_root/gimps/...64.service.zip
Windows Service 32-bit: https://mersenne.org/ftp_root/gimps/...32.service.zip
13.03.2021

Changelog:

1) Faster P-1 stage 2.
2) Faster ECM stage 1 and stage 2.
3) Gwnum library overhauled. Many functions deprecated. Replaced by more powerful gwmul3. New functions that compute (a+b)*c and (a-b)*c with less memory accesses. Faster conversion to and from binary.
4) ECM and P-1 can find the best B2 value for the amount of memory prime95 is allowed to use. For ECM, this happens when the worktodo.txt line sets B2=100*B1 which is the default assignment from the PrimeNet server. For P-1, the best B2 is chosen when the worktodo.txt line specifies the trial factoring depth. For example, "Pminus1=1,2,20000003,-1,500000,0,70" chooses the best B2 bound for B1=500000 given that M20000003 has been trial factored to 2^70.
23.01.2021

Changelog:

1) Faster P-1 stage 2.
2) Faster ECM stage 1 and stage 2.
3) Gwnum library overhauled. Many functions deprecated. Replaced by more powerful gwmul3. New functions that compute (a+b)*c and (a-b)*c with less memory accesses. Faster conversion to and from binary.
4) ECM and P-1 can find the best B2 value for the amount of memory prime95 is allowed to use. For ECM, this happens when the worktodo.txt line sets B2=100*B1 which is the default assignment from the PrimeNet server. For P-1, the best B2 is chosen when the worktodo.txt line specifies the trial factoring depth. For example, "Pminus1=1,2,20000003,-1,500000,0,70" chooses the best B2 bound for B1=500000 given that M20000003 has been trial factored to 2^70.
11.09.2020

Changelog:

1) 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.
2) Proofs automatically uploaded to server in v30.2.
3) First time LL, World-record LL, 100M-digit LL work preference is deprecated.
4) 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.
5) LL-DC and PRP-DC combined into a single work preference.
6) Warning raised if temporary disk space is less than 1.5GB -- you may not get first time prime tests.
7) Thanks to Mihai Preda, the P-1 probability calculator has been improved. This change results in a
lower optimal B1 value and higher optimal B2 value.
10.08.2020

Changelog:

1) 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.
2) Proofs automatically uploaded to server in v30.2.
3) First time LL, World-record LL, 100M-digit LL work preference is deprecated.
4) 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.
5) LL-DC and PRP-DC combined into a single work preference.
6) Warning raised if temporary disk space is less than 1.5GB -- you may not get first time prime tests.

Downloads Prime95 30.3 build 1 vom 10.08.2020:
18.08.2019

Changelog:

  1. Support added for AVX-512 FFTs.
  2. FMA3 FFTs now have slightly higher FFT crossover points. Soft crossovers are no longer used by default. See undoc.txt.
  3. Torture test dialog box options now based on cache sizes. Options for performing a weaker torture test are available. Torture tests that use all RAM are now more stressful. In-place vs. not in-place memory accesses now displayed on screen. On machines with more than 4GB of memory, blend defaults to 1/16th of RAM.
  4. Add & subtract operations for AVX-512 FFTs are now multithreaded. This should improve performance for P‑1 and ECM when using multiple threads.
  5. Benchmark results are now written to results.bench.txt.
  6. JSON results are now available for all work performed. JSON results are written to results.json.txt.
  7. PRP tests with Gerbicz error checking are more immune to hardware errors.

Downloads Prime95 29.8 build 6 vom 18.08.2019:
Oben Unten