On 3 December 2017, 06:30:24 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:
The prime is 1,721,010 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 6th for Generalized Fermat primes and 53rd overall.
The discovery was made by Sean Humphries (No.15) of the United States using an AMD Radeon RX Vega in an AMD Ryzen 7 1800X CPU with 32GB RAM, running Microsoft Windows 10 Professional Edition. This GPU took about 24 minutes to probable prime (PRP) test with GeneferOCL5. Sean is a member of the Overclock.net team.
The prime was verified on 3 December 2017, 07:29:36 UTC by Wolfgang Schwieger (DeleteNull) of Germany using an NVidia GeForce GTX Titan Black GPU in an Intel(R) Core(TM) i7-6700K CPU at 4.00GHz with 32GB RAM, running Linux. This GPU took about 27 minutes to probable prime (PRP) test with GeneferOCL5. Wolfgang is a member of the SETI.Germany team.
The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Microsoft Windows 10 Professional Edition. This computer took about 5 hours 45 minutes to complete the primality test using multithreaded LLR.
For more details, please see the official announcement.