I have a L312B342 and i havent testedt it at 5ghz, but it did wprime 32m 4c/8t at 5,2ghz with Water and about 1.35v
And wprime 1024 at 5.1ghz at the same volt
And it did cinebench at 5.8ghz under dice after i learned the new system and ran out of dice but in 2 weeks i have a bench session with my teammates and then it goes under Ln2