i had a similar concern when i got my r7 2700x last year. i went crazy trying to figure it out because i was idling 40-50c. i ended up just using built in windows power saver settings. when i'm just screwing around not doing anything intensive, i set it to power saver mode and i idle around 25-30c. when i want to play a game, i switch windows setting to high performance and the increase in power brings the temp up 20 degrees c almost instantly.