What's New: New Features in Version 19.x of Prime95

# NEW FEATURES IN VERSION 19.x of PRIME95.EXE

## New Features in Version 19.2 of Prime95

1. A bug in factoring exponents above 35.79 million was fixed.

## New Features in Version 19.1 of Prime95

1. A new undocumented feature, Stage1 GCD, lets you speed up P-1 tests on large exponents - see undoc.txt for details.
2. K6 CPUs now default to the Pentium code path instead of the Pentium Pro code path. This is faster on the K6.
3. The rolling average formula was adjusted to work better on machines that are not on 24 hours a day.

## New features in Version 19.0 of Prime95

1. Faster - in some cases as much as 10% faster!. The FFTs were recoded for improved memory and TLB efficiency. Furthermore, optimizations specific to the Pentium Pro and later processors were added.
2. New FFT lengths. The program can now test exponents as large as 79.3 million. Also, smaller FFT lengths are supported for use in ECM and P-1 factoring.
3. More conservative FFT breakpoints. This could actually result in some exponents being slower to test in this version. However, the chance of a fatal rounding error has been reduced.
4. P-1 factoring has been added. Although it is not very practical for large exponents because of a slow GCD routine, it can be used to find new factors of exponents below a few million or so.
5. ECM can now run on large exponents. Once again, the slow GCD routine and high memory requirements might make this impractical for large exponents.
6. ECM and P-1 factoring now support save files. Very handy on lengthy runs. The count of completed ECM curves is maintained in the save file instead of the worktodo.ini file.
7. ECM and P-1 factoring lets you specify the amount of memory to use. In some cases, more memory can improve execution speed slightly.
8. A bug in guessing the CPU speed on initial install has been fixed.
9. The preferences dialog now has an option to pause prime95 when a laptop is running on its battery.
10. Error checking has been improved slightly.
11. Factoring is now "layered". That is, prime95 now factors to 2^50, then 2^51, 2^52, and so forth up to the appropriate limit. The factoring output lines have been changed to show percent complete in the current "layer".
12. A bug in running two or more self or torture tests in the same directory has been fixed.
13. Trial factoring above 2^64 is now supported.
14. More trial factoring is now done to take into account the cost of double-checking.
15. Title now contains percent complete when LL testing. By default, the percent complete value is now displayed to 2 decimal places. You can change this by setting PercentPrecision in prime.ini to a value between 0 and 6.
16. Affinity and service name settings moved from prime.ini to local.ini file. Prime95 will automatically move these settings for you.
17. An option to get only 10,000,000 digit numbers to run primality tests on has been added to the Test/Primenet dialog box. See http://www.mersenne.org/prize.htm for rules on claiming the EFF award for finding a 10,000,000 digit prime.
18. The Advanced/Clear primes menu choice has been deleted.
19. The prime95 icon turns yellow when the program is idle. After an error such as ILLEGAL SUMOUT, the icon will blink for 10 seconds.
20. The User Information dialog box allows you to request newsletters and form a team user ID where the team members cannot alter the team name.
21. A bug in the reporting of error counts in the results.txt file has been fixed.
22. The server can now broadcast important messages to the prime95 client. Prime95 will blink the icon until prime95 is activated and then it will display the message.
23. A computer ID will be generated for computers that do not have one. If you want to assign your own computer ID, please try to make each computer ID using the same user ID unique.