On 16 March 2020, 08:21:46, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=207494 by finding the mega prime:
The prime is 2,109,149 digits long and enters Chris Caldwell's “The Largest Known Primes Database” ranked 75th overall and is the largest known base 5 prime. 63 k’s now remain in the Riesel Base 5 problem.
The discovery was made by Todd Pickering (EXT64) of the United States using an AMD EPYC 7601 32-Core Processor with 126GB RAM, running Linux Ubuntu. This computer took about 1 day, 17 hours, 59 minutes to complete the primality test using LLR. Todd Pickering is a member of the [H]ard|OCP team.
The prime was verified internally using an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 32GB RAM, running Linux Debian.
For more details, please see the official announcement.