Ryzen processor who does not want to go up to 3.9 MHZ with game boost

Hello, I have a question: I have a 1500x ryzen boosted to 3.7 mhz, I can not go up to 3.9, yet I managed to climb up to the passing through game boost, I have a Hyper tx3 evo with a temperature that does not exceed 60 ° after a few hours of play: my config: ryzen 1500x, motherboard MSI Tomahawk B 350 (Bios a day), 8 GB of ram Ballistik 2x4 2400, why I do not arrive to reach 3.9 mhz? thank you

 

PS : escuse my english, i'm french