If you want to play it safe yes stress it 2 hours, if not you can always just use it and if you run into issues, freezing, BSOD etc. You can always stress it then, though for me I'd stress it. What I would do is this, open Hwmonitor and run Prime or Occt for 20 minutes, look at what the Cpu Nb voltage did under load and then set it manually to that voltage. Then raise the Cpu Nb freq to 2200 and stress it. Most Fx cpu's will run the Nb freq at 2400-2600 Mhz. My 8350 needed a kick in the pants at 2600 to 1.3875v. Note that raising the Cpu Nb voltage will raise the temps under load slightly.