[QUOTE=James Heinrich;603545]..Please don't do P-1 badly, you'll miss factors unnecessarily and (if done badly enough) people may need to re-do your work, which is the definition of inefficient.[/QUOTE]

[I]Prime95[/I] establishes its own P-1 and ECM bounds and I don't change them. If there is a difference between v29 and v30, I am unaware of it. I have no intention of doing anything "badly." This would be unnecessary work for someone else. I don't what that!

[QUOTE=storm5510;603567]If there is a difference between v29 and v30, I am unaware of it.[/QUOTE]There is. A huge difference. Since you posted about this in the v30.8 thread I assume you have been reading about it and are aware of the differences. In short, v30.8 can work with [i]significantly[/i] higher bounds for [i]significantly[/i] higher chance of factor for the same amount of allocated RAM.

[QUOTE=James Heinrich;603568]There is. A huge difference. Since you posted about this in the v30.8 thread I assume you have been reading about it and are aware of the differences. In short, v30.8 can work with [i]significantly[/i] higher bounds for [i]significantly[/i] higher chance of factor for the same amount of allocated RAM.[/QUOTE]

I have 30.8 installed on two machines but have not been using it. I will give it another look.

Found two factors for a TWOK candidate. one factor in stage one, one factor in stage two.
Both were missed by a 2003 P-1; both could be found with small B1, B2 so the large B2 from 30.8 was a little unnecessary.

[M]19442623[/M] has a 82-bit (25-digit) factor: [url=https://www.mersenne.ca/M19442623]7705180804505006995733009[/url] (P-1,B1=800000)
[M]19442623[/M] has a 78-bit (24-digit) factor: [url=https://www.mersenne.ca/M19442623]152612436387610563716369[/url] (P-1,B1=800000,B2=802202310)

Composite factor
 

[M]112084657[/M]

P-1 found a 238-bit composite factor(B1=824000, B2=242053350).

[URL="https://www.mersenne.ca/factor/408942596393398983090401"]408942596393398983090401[/URL] - 78.436bits
[URL="https://www.mersenne.ca/factor/1600346782413225832691898697103973353256067499521"]1600346782413225832691898697103973353256067499521[/URL] - 160.131bits

[QUOTE=Jan S;604448][URL="https://www.mersenne.ca/factor/1600346782413225832691898697103973353256067499521"]1600346782413225832691898697103973353256067499521[/URL] - 160.131bits[/QUOTE]That is a top 5 all time P-1 factor. Congrats!!

[QUOTE=Jan S;604448][M]112084657[/M]

P-1 found a 238-bit composite factor(B1=824000, B2=242053350).

[URL="https://www.mersenne.ca/factor/408942596393398983090401"]408942596393398983090401[/URL] - 78.436bits
[URL="https://www.mersenne.ca/factor/1600346782413225832691898697103973353256067499521"]1600346782413225832691898697103973353256067499521[/URL] - 160.131bits[/QUOTE]

Impressive - nice find!

[QUOTE=Uncwilly;604449]That [STRIKE]is[/STRIKE] would have been* a top 5 all time P-1 factor. Congrats!![/QUOTE]
Would have been if it were prime.
Composite factors' sizes are arbitrarily large and don't count.

[QUOTE=lycorn;601499]Speaking of composite factors, I found this beauty some days ago:

UID: lycorn/supernova, ...[/QUOTE]

[QUOTE=Batalov;604480]Would have been if it were prime.[/QUOTE]No, just the 160-bit prime component of the composite factor is #5 on the [URL="https://www.mersenne.ca/userfactors/pm1/1/bits"]biggest P-1 Mersenne Factors list[/URL].

Ah, ok.
That message said "a top 5 all time P-1 factor" (period). I know a thing or two about top all time P-1 factors - they are [URL="https://members.loria.fr/PZimmermann/records/Pminus1.html"]way larger[/URL].

P-1 found a factor in stage #2, B1=490000, B2=13987000.
UID: Jwb52z/Clay, M114782309 has a factor: 274973054029559054066929 (P-1, B1=490000, B2=13987000)

77.864 bits.