Welcome to the PrimeGrid Valentine's Day Challenge. PrimeGrid is running a short, one-day challenge to find primes, and maybe find a record Sophie Germain prime. Overall I'd say this is your third-best chance to find a top-5000 prime this year. What you need: One or more fast x86 processors. (Even slow ones will do!) Windows, Linux, or MacOS 10.4+. BOINC, attached to PrimeGrid (http://www.primegrid.com/). Your PrimeGrid Preferences with only "Sophie Germain Prime Search (LLR)" selected in the Projects section. What may help: An Intel processor with AVX. (AVX doesn't help AMD.) A 64-bit Windows OS may be slightly faster than other OSes. What won't help (but won't hurt either): A large amount of RAM. Any video cards. This challenge starts Valentine's Day, February 14 at 18:00 UTC, and runs for only 24 hours. Work not downloaded and uploaded within the challenge will not be counted. Should you not be able to be in front of one or more computers at that time, just set their queue level very low (0.01 days). This also makes it more likely that you will be a prime finder rather than a double-checker. Welcome and good luck to all!