On 21 September 2014, 18:43:31 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=325918 by finding the mega prime:
The prime is 1,260,486 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 58th overall. This is the largest known base 5 mega prime. 79 k's now remain in the Riesel Base 5 Problem.
The discovery was made by Jörg Meili (meilijo) of Switzerland using an Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz with 8GB RAM running Microsoft Windows 7 Home Premium. This computer took about 20 hours and 51 minutes to complete the primality test using LLR. Jörg is a member of the Aggie the Pew team.
The prime was verified on 1 October 2014, 12:57:59 UTC by Yegor Ryabchikov (Yegor001) of Russia using an Intel(R) Core(TM) i5 CPU 760 @ 2.80GHz with 2GB RAM running Microsoft Windows 7 Home Basic. This computer took about 133 hours 16 minutes to complete the primality test using LLR.
For more details, please see the official announcement.