Utilization is fine. A CPU could run 100% utilization, 24/7 for years without issue - provided voltages & temperatures are in check.
81'C is a bit on the warm side, for a CPU not under a torture workload (Prime95 etc). Is that a sustained temp? Or a very brief 'peak'? Generally, you'd want to see <80'C.
What are you using to monitor temperatures?
What is your ambient temperature?
What cooler are you using?
What case are you using?