In the September $500 budget gaming build (http://www.tomshardware.com/reviews/phenom-ii-overclock...), they had a Phenom II X4 955 @ 125W and an HD 6870 @ 247W at full load according to bit-tech.com (254W according to Maximum PC.com), which adds up to 372W. The PSU they used, which I also have, is an Antec Earthwatts 430W and can allow for 384W on the 12V rails.
So my question is....
How in the world is that system (http://www.tomshardware.com/reviews/phenom-ii-overclock...) only drawing 317W, AND while being overclocked, with CPU and GPU at FULL LOAD? According to my above calculations, it should be drawing 372W at least, without even factoring in added 12V wattage from the case fans, drive motors, RAM, etc. What's going on here? Any insight would be greatly appreciated. Thanks!
Because the cpu's TDP of 125 is NOT the amount of wattage it draws .
Its the amount of wattage it can draw before it starts to shut its self down to prevent damage . It has much more to do with the design of the processor package and recommended coolers than it does with power consumption
Worse still intel and AMD have no common way of measuring or deciding what a TDP should be
The graphics card numbers you have there are completely wrong too. An entire phenom/6870 rig probably pulls around 260 - 270 watts