I haven't seen a PC power supply that is not an SMPS (Switch Mode Power Supply) in well over 25 years. An SMPS rectifies AC to DC and changes the DC output voltage using PWM firing of transistors. So in the initial process of rectifying to DC, it could not care less if it is 50 or 60Hz, it's just a passive diode bridge rectifier making DC from it anyway. At the power levels used by PCs now, a linear power supply would likely be 4 times the size of a modern power supply. So if it's a laptop, the cord connected PSU would be about the same size ass the laptop itself.
And I have not seen an AC sourced clock pulse generator in that long as well.