On 8 Aug 2012, 8:58:58 UTC, PrimeGrid’s Generalized Fermat Prime Search found the largest known Generalized Fermat mega prime:
The prime is 2,976,633 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Generalized Fermat primes and 11th overall.
The discovery was made by Masashi Kumagai (ragnarag) of Japan using an NVIDIA GeForce GTS 450 in an AMD FX(tm)-8150 CPU with 8GB RAM, running 64 bit Windows 7. This GPU took 7 hours 47 minutes to probable prime (PRP) test with GeneferCUDA. Masashi Kumagai is a member of the Team 2ch team.
The prime was verified by Jason Preszler (Jason Preszler) of the United States using an Intel Core i7-2600 CPU @ 3.40GHz with 12GB RAM, running 64 bit LINUX . This computer took 46 hours 55 minutes to probable prime (PRP) test with GenefX64. Jason is a member of the Turan@BOINC team.
For more details, please see the official announcement.