get something like MSI afterburner or Cortemp to monitor Core load and temperature. then download either the intel burn test ( get it from major geeks website and make sure to avoid the fake download buttons) or for single core get Super Pi then watch the temps ( both will push 100% load. depending on how old you chip is, prime 95 is also a great candidate, but on the newer ones it just makes absurd amounts of heat to the point at which things can be broken.