What's New: New Features in Version 24.x of Prime95

# NEW FEATURES IN VERSION 24.x of PRIME95.EXE

## New Features in Version 24.14 of Prime95

1. A bug that caused the torture test to hang on 256K FFTs on SSE2 machines with 128K of L2 cache was fixed.

## New Features in Version 24.13 of Prime95

2. Celeron D (256K L2 cache) and Willamette (also 256K L2 cache) now have different implementations for several FFT sizes. This results in an improvement of several percent for the Celeron D.

3. A bug that caused some machines to generate "Error 2252" when communicating with the server was fixed.

4. SSE2 trial factoring code had a bug when factoring very large exponents.

## New Features in Version 24.12 of Prime95

1. For SSE2 machines the larger FFTs have been changed to more effectively use a wide variety of L2 cache sizes. The previous version was optimized for a 256KB L2 cache only. Depending on your CPU and FFT size, you could see an improvement of several percent.

2. As a side "benefit" even larger FFT sizes are now supported. This allows testing of exponents up to 596 million. Not recommended.

3. The factoring breakeven points have been recalculated using my 2 GHz P4. This version of prime95 will do less trial factoring.

4. Since server database crashes cause spurious error 3 messages, prime95 will now ignore error 3 messages from the server for 72 hours. This should workaround the problem whereby a result is reported but no CPU credit is given and the reservation is not cleared.

5. Fixed crash bug trial factoring exponents above 286 million.

## New Features in Version 24.11 of Prime95

1. Faster FFTs for AMD64 using prefetchw in both 32-bit and 64-bit mode. You can expect about a 15% speed improvement.

2. Prime95 now detects support for 3DNow! instructions. See undoc.txt for overriding this detection with CpuSupports3DNow=n in local.ini.

3. Factoring entries in worktodo.ini now accept exponents up to 2 billion.

4. Improved checking for memory allocation errors during a torture test. Better guessing of amount of memory to use in a blend test.

5. Added timeouts to PrimeNet communications in hopes of avoiding rare hangs when contacting the PrimeNet server.

6. Fixed rare bug where P-1's GCD could miss a factor.

7. Added trial factoring to the benchmark.

8. Fixed bug in ECM when using zero-padded FFTs.

9. SSE2 macros optimized for an additional 1-3% improvement on P4 and AMD64 CPUs.

## New features in Version 24.10 of Prime95

1. 64-bit version of prime95 available for 64-bit Windows.

## New features in Version 24.9 of Prime95

1. Fixed crash when running on machines with "no-execute" protection.

2. Fixed mis-detection of some P3 and Celeron CPUs.

## New features in Version 24.6 of Prime95

1. Athlon users should see a 20% to 30% speed increase.

2. Pentium, Pentium II, Pentium III users should see dramatically WORSE performance. Run version 23 instead.

3. P-1 and ECM now support numbers of the form k*b^n+c. This cannot be done from the menus. Add these entries to worktodo.ini:

Pminus1=k,b,n,c,B1,B2
ECM2=k,b,n,c,B1,B2,curves_to_do[,specific_sigma]

##