On 21 March 2014, 13:39:54 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=330286 by finding the mega prime:
The prime is 1,107,453 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 57th overall. This is the largest known base 5 mega prime. 85 k's now remain in the Riesel Base 5 Problem.
The discovery was made by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz with 4GB RAM running Microsoft Windows 7 Enterprise. This computer took about 35 hours and 55 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.
The prime was verified on 23 March 2014 10:55:21 UTC, by Baneus of Germany using an AuthenticAMD Quad-Core AMD Opteron(tm) Processor 2356 with 64 GB RAM running Linux. This computer took about 73 hours and 11 minutes to complete the primality test using LLR.
For more details, please see the official announcement.