are those DTS core temps? or motherboard temps? the latter is when you are using your mobos software. DTS core temps are usually +10C compared to what the mobo reads. if thats is a mobo temp, then thats hot but still within operating temps. since you are using a stock cooler thats very normal and to be expected. a high percentage of PCs including workstations operate on up to 75C. nothing to worry here. only worry if those temps are at a constant 85~90C.
if your idle temps are lower then 35C. then your cooler is working normally.
you can get the cheapest but effective substitute to your stock cooler like the CoolerMaster Hyper212 Evo/Noctua NHL9S to improve high usage temps by minus 5~10C