PrimeGrid Challenge Series 2026

[Ken g6]

PrimeGrid's 2026 Challenge Series:

1​	16-23 January​	20:00:00	ESP	World Nothing Day Challenge	7 days
2​	7-17 March​	10:00:00	SoB	Telephone Challenge	10 days
3​	3-10 June​	21:00:00	321	h4ck3r's Birthday Challenge	7 days
4​	16-21 July​	16:00:00	Primorial	World Snake Day Challenge	5 days
5​	12-15 August​	05:00:00	PPSE	Perseid Meteor Shower Challenge	3 days
6​	7-12 September​	14:41:00	SR5	Baengno Challenge	5 days
7​	2-7 October​	17:00:00	GFN19	Suzuki's Birthday Challenge	5 days
8​	6-13 November​	18:00:00	GCW	Lehmer's Birthday Challenge	7 days
9​	18-28 December​	22:00:00	GFN22	Photon Challenge	10 days

I found a good guide to setting up PG on TheFPS review, mostly by Skillz.

And an old quote:

Scores will be kept for individuals and teams. Only tasks issued AFTER [the challenge start time] and BEFORE [the challenge end time] will be considered for credit. We will be using the same scoring method as we currently use for BOINC credits. A quorum of 2 is NOT needed to award Challenge score - i.e. no double checker. Therefore, each returned result will earn a Challenge score. Please note that if the result is eventually declared invalid, the score will be removed.

 

[Ken g6]

And we're off for another year!

 

[Ken g6]

Day 1 stats:

Rank___Credits____Username
1______6009132____Icecold
3______4682139____markfw
5______3193952____crashtech
9______2162968____cellarnoise2
36_____526576_____mmonnin
43_____436060_____w a h
73_____205959_____Orange Kid
75_____167161___10esseeTony
87_____110062_____Ken_g6
109____101131_____johnnevermind

Rank__Credits____Team
1_____17595145___TeAm AnandTech
2_____9911824____Czech National Team
3_____7457796____SETI.Germany
4_____6369046____BOINC@AUSTRALIA

 

[Markfw]

I'm only running 5 boxes and 2nd in the team and 3rd overall ? I guess I am lucky.

 

[Ken g6]

I'm only running 5 boxes and 2nd in the team and 3rd overall ? I guess I am lucky.

Depends on the kind of box. I'm running 3, but only 2 have reported so far.

 

[Markfw]

Depends on the kind of box. I'm running 3, but only 2 have reported so far.

2 9755, 2 7950x and one 9554.

 

[Ken g6]

Day 2 stats:

Rank___Credits____Username
1______15996387___Icecold
4______9912425____markfw
7______7272899____cellarnoise2
8______7039102____crashtech
28_____1977013____w a h
39_____1339345____mmonnin
59_____704005_____johnnevermind
68_____547080___10esseeTony
71_____531539_____Orange Kid
92_____326512_____Ken_g6
160____106806_____waffleironhead

Rank__Credits____Team
1_____45753118___TeAm AnandTech
2_____26013274___Czech National Team
3_____21759409___BOINC@AUSTRALIA
4_____18907726___SETI.Germany

 

[Ken g6]

Day 3 stats:

Rank___Credits____Username
1______25161555___Icecold
5______15560800___markfw
7______10639725___crashtech
9______9993599____cellarnoise2
20_____5281035____w a h
38_____2164418____mmonnin
60_____1140489___10esseeTony
63_____1085307____johnnevermind
72_____864417_____Orange Kid
86_____605916_____Ken_g6
159____218427_____waffleironhead
214____102263_____mnelsonx
258____36605______ChelseaOilman

Rank__Credits____Team
1_____72854561___TeAm AnandTech
2_____43066189___Czech National Team
3_____38736579___BOINC@AUSTRALIA
4_____29347366___SETI.Germany

 

[Ken g6]

Day 4 stats:

Rank___Credits____Username
1______34958651___Icecold
5______22995723___markfw
7______14318765___crashtech
9______13074034___cellarnoise2
22_____6855912____w a h
41_____2762399____mmonnin
58_____1728833___10esseeTony
67_____1406350____johnnevermind
75_____1192804____Orange Kid
98_____774558_____Ken_g6
139____486268_____ChelseaOilman
145____438279_____waffleironhead
256____102263_____mnelsonx

Rank__Credits____Team
1_____101094845___TeAm AnandTech
2_____61190183___Czech National Team
3_____57422668___BOINC@AUSTRALIA
4_____42797056___SETI.Germany

We're the first to 100M K.

 

[Markfw]

Day 4 stats:



We're the first to 100K.

You mean 100 million ? Team score ?

 

[StefanR5R]

Day 4 stats:
We're the first to 100M

...in any ESP-LLR challenge ever. The previous three (March 2024, November 2023, June 2021) went only for 5 days each, and the TeAm won them with 93 M, 90 M, and 47 M respectively.

 

[Ken g6]

After many years of service, looks like one of my computers gave up the ghost. (@TennesseeTony 's BumbleBee.) It boots to BIOS, but otherwise gets stuck on the splash screen.

 

[Icecold]

After many years of service, looks like one of my computers gave up the ghost. (@TennesseeTony 's BumbleBee.) It boots to BIOS, but otherwise gets stuck on the splash screen.

I've had that happen before when I had an SSD fail. Might not be the issue but I'd try unplugging any drives plugged into it and see if it makes a difference. Hardware issues are definitely a bummer though.

 

[Ken g6]

Day 5 stats:

Rank___Credits____Username
1______44351555___Icecold
5______29416061___markfw
7______17879264___crashtech
9______15526249___cellarnoise2
24_____7480732____w a h
28_____5486705____ChelseaOilman
48_____2875122____mmonnin
60_____2267228___10esseeTony
71_____1844375____johnnevermind
80_____1465972____Orange Kid
103____997068_____Ken_g6
129____725882_____waffleironhead
273____102263_____mnelsonx

Rank__Credits____Team
1_____130418481___TeAm AnandTech
2_____77473271___Czech National Team
3_____76520545___BOINC@AUSTRALIA
4_____53864555___SETI.Germany

 

[Ken g6]

Day 6 stats:

Rank___Credits____Username
1______51730661___Icecold
5______35875555___markfw
8______21983496___crashtech
10_____18024404___cellarnoise2
18_____11439987___ChelseaOilman
25_____8162710____w a h
59_____2875122____mmonnin
65_____2545657___10esseeTony
69_____2347151____johnnevermind
79_____1803438____Orange Kid
108____1162726____Ken_g6
138____844090_____waffleironhead
212____328573_____mnelsonx
315____50286______DROFFUNGUS

Rank__Credits____Team
1_____159173862__TeAm AnandTech
2_____96744101___Czech National Team
3_____95569430___BOINC@AUSTRALIA
4_____64187349___SETI.Germany

I've had that happen before when I had an SSD fail. Might not be the issue but I'd try unplugging any drives plugged into it and see if it makes a difference. Hardware issues are definitely a bummer though.

Didn't help. And now it's not even booting to BIOS.

 

[Ken g6]

More-or-less final stats:

Rank___Credits____Username
1______60291708___Icecold
5______42572534___markfw
7______31658380___cellarnoise2
8______28342506___ChelseaOilman
10_____25838607___crashtech
26_____8827340____w a h
67_____2875122____mmonnin
69_____2849400____johnnevermind
77_____2545657___10esseeTony
81_____2081294____Orange Kid
117____1266975____Ken_g6
138____1015171____waffleironhead
186____550878_____mnelsonx
237____278704_____DROFFUNGUS

Rank__Credits____Team
1_____210994280___TeAm AnandTech
2_____114633889___BOINC@AUSTRALIA
3_____113568597___Czech National Team
4_____82342125___SETI.Germany

 

[Markfw]

Tour de primes coming in one day. What is the project ? I don't see it ?

 

[Ken g6]

Tour de primes coming in one day. What is the project ? I don't see it ?

It's not a PrimeGrid Challenge Series Challenge; it's more informal than that. It's a competition to actually find large primes; here, WUs that don't find a prime don't count for anything.

If you want to take part you can run any project that isn't a sieve. The project most likely to find a reportable prime right now is GFN-17. You can see this on the PrimeGrid home page - it's the project with the largest Prime Rank that's not "5K+". All other projects with a numerical prime rank not "5K+" would count if you found a prime. With other projects the chances are lower to find the largest number of primes in the competition, but your chances of finding the largest prime in the competition, or the largest total prime score in the competition, might improve. They hand out jersey badges for those, but most of us are lucky to get a "P" badge for finding any large prime.

 

[Markfw]

It's not a PrimeGrid Challenge Series Challenge; it's more informal than that. It's a competition to actually find large primes; here, WUs that don't find a prime don't count for anything.

If you want to take part you can run any project that isn't a sieve. The project most likely to find a reportable prime right now is GFN-17. You can see this on the PrimeGrid home page - it's the project with the largest Prime Rank that's not "5K+". All other projects with a numerical prime rank not "5K+" would count if you found a prime. With other projects the chances are lower to find the largest number of primes in the competition, but your chances of finding the largest prime in the competition, or the largest total prime score in the competition, might improve. They hand out jersey badges for those, but most of us are lucky to get a "P" badge for finding any large prime.

Well, since last year I found the 2nd largest prime ever (for primegrid), I think I will pass on this , based on my recent problems.

Thanks for the info.

 

[Markfw]

well, I put one machine on PG gfn17 and bam !

Congratulations! Our records indicate that a computer registered by you has found a unique prime number. This computer is running BOINC, is attached to the PrimeGrid project, and is assigned to the Generalized Fermat Prime Search n=17 Mega (GFN-17-Mega). What makes this prime unique is that it's large enough to enter the Top 5000 List in The Largest Known Primes Database.

Since you have auto-reporting selected, the following prime was submitted on your behalf:

Added 141664 : 423478978^131072+1 (1130737 digits)

 

[Rollo]

Received a email this morning informing me I had found a large Prime, but I don't see it recorded anywhere. Says top 5000...

 

[Ken g6]

Received a email this morning informing me I had found a large Prime, but I don't see it recorded anywhere.

It takes awhile before they verify your number is prime, using a different program. In the meantime, its status should be listed here:

PrimePage Primes: Prime Verification Status

t5k.org

 

[Rollo]

Guess this is it? https://t5k.org/primes/page.php?id=141781

Added 141781 : 436197732^131072+1 (1132421 digits)