Simulator - Different profiling results on different PCs

How accurate is the simulator i.t.o. performance profiling? I'm getting different results on 2 different PCs for the same watch face + device and test run. Do the specs of the PC really influence the results like it seems to be doing for me? Sim version is 6.4.2. I would have expected the sim to have a clock speed of some sorts and run basically the same on most PCs, except maybe ones that are underpowered, which i don't think mine are if I look at cpu usage while using the sim.