On 15 August 2018, 03:15:13 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=194368 by finding the mega prime:
The prime is 1,843,920 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 60th overall and is the largest known base 5 prime. 69 k's now remain in the Riesel Base 5 Problem.
The discovery was made by Honza Cholt (Honza) of the Czech Republic using an Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz with 20 GB RAM running Microsoft Windows Server 2016. This computer took about 4 hours 44 minutes to complete the primality test using multithreaded LLR. Honza is a member of the Czech National Team.
The prime was verified on 17 August 2018, 10:15:20 UTC by Deano Montreuil (Deano Montreuil) of the United States using an Intel(R) Core(TM) i5-2400 CPU @ 3.10GHz with 8 GB RAM running Microsoft Windows 10 Core Edition. This computer took about 61 hours 55 minutes to complete the primality test using LLR. Deano is a member of the Aggie The Pew team.
For more details, please see the official announcement.