If motherboard does it right, only EPS12V connector is used for CPU. If motherboard does it wrong, there's no much sense in using it for testing stuff.
Buying a EPS12V connector extension cable (even 10 inches would be enough), bridging the grounds (so there's just one fat ground) and running it through a high-end amp meter, then multiplying by 12 (voltage) to get watts.
Yeah, considering how well you did at physics..
Believing that 0.00001mm pins can carry 388 amps is like believing what Intel-sponsored malvertisers say.. and you do!
You do realize that only two of 8-core models draw 125W, every other ones (eight-core 8120/8100, six core 6120/6100 and quad core 4120/4100) are 95W just like i5 2500K / i7 2600K?