# AdvancedFactor

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**AdvancedFactor** is one of the undocumented options for Prime95, which was removed in later versions. The format for the line you add to the worktodo.ini file is:

`AdvancedFactor=start_exponent, end_exponent, b1, b2`

where:

- start_exponent is the first exponent in a range to test.
- end_exponent is the last exponent in a range to test.
- b1 is the starting bit-depth to test with.
- b2 is the ending bit-depth to test with.

The line:

`AdvancedFactor=1000000, 2000000, 64, 68`

would attempt to trial-factor every prime exponent between 1,000,000 and 2,000,000 for factors between 2^{64} and 2^{68}.

If you don't want to check a range of exponents, and instead just want to check a specific set of exponents, you need to use the line in worktodo.ini:

`Factor=exp, bd`

where:

- exp is the exponent to trail-factor.
- bd is where to begin trial-factoring at (2
^{bd}).

The line:

`Factor=42099977, 61`

would attempt to trial-factor the exponent 42,099,977 starting at 2^{61} and continue until it either found a factor or reached 2^{69} (Prime95's default breakpoint for this exponent), unless you used the FactorOverride line in prime.ini.

If you put say:

`FactorOverride=66`

in prime.ini, Prime95 would attempt to factor it only up to 2^{66} instead of 2^{69}.

You would have to put a Factor= line in worktodo.ini for each and every exponent you wanted to test.

If you are using the most recent version of Prime95, v24.14, it will accept exponents to trial-factor up to 2 Billion. While none of the documentation says specifically, looking at the source code, it would appear that Prime95 can do SSE2 factoring up to 2^{86} and non-SSE2 factoring up to 2^{96}.