Hi there i have connect 3 lamps in parallel with PC Power supply's +12 output. I have 2 watt meter clamp type. I both measure DC part and AC part at the same time here's the results:

DC Part

E(V) 11.4Volts
I(A) 5.25Amps
P(W) 60Watts

AC Part

E(V) 200V
I(A) 0.47A
RealPower(W) 72Watts
ApparentPower(VA) 94VA
ReactivePower(VAR) 60VAR
PowerFactor(%) 0.77

so above the results the wasted power is 16.56W is it right?

and efficiency= dc output/ac in=0.83 is it right?

i only loaded just +12V output the other rails unloaded
sorry my bad English thank you very much

 

I would say it is 72-60=12W loss. Usually electricity meters (like for a house) measure real power, not apparent. Efficiency is 60/72=0.83.