On 30 June 2017, 02:54:43 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:
The prime is 1,700,222 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 5th for Generalized Fermat primes and 50th overall.
The discovery was made by Sean Humphries (No.15) of the United States using an NVIDIA GeForce GTX 1080 in an Intel(R) Xeon(R) E5-2670 CPU at 2.60GHz with 32GB RAM, running Linux. This GPU took about 16 minutes to probable prime (PRP) test with GeneferOCL3. Sean is a member of the Overclock.net team.
The prime was verified on 1 July 2017, 18:49:46 UTC by John Hall (JH30895) of the United States using an NVIDIA GeForce GTX 680 in a dual Intel(R) Xeon(R) X5680 CPU @ 3.33 GHz with 24GB RAM, running macOS Sierra. This GPU took about 52 minutes to probable prime (PRP) test with GeneferOCL5. John is a member of the Ars Technica 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. This computer took about 4 hours 18 minutes to complete the primality test using LLR.
For more details, please see the official announcement.