3 ms·

Hmm maybe I'm wrong. I vividly remember an equation for the power consumption of a CPU, and it definitely had a f^2 in it. However, I currently can't derive it

by nom 10y ago

Hmm maybe I'm wrong. I vividly remember an equation for the power consumption of a CPU, and it definitely had a f^2 in it. However, I currently can't derive it anymore (and it was definitely a simplification). I'll try to pull up the slides later. It's probably outdated, the influence of the individual factors may have changed. In the meantime I can only offer this [1] stackexchange post. Power of a CPU is definitely quadratic in f, or even worse. [1] http://physics.stackexchange.com/questions/34766/how-does-power-consumption-vary-with-the-processor-frequency-in-a-typical-comput http://physics.stackexchange.com/questions/34766/how-does-po... edit: I probably remembered it wrong and I now think that that the equation was P=C x V^2 x f. However, transition power effectively has an exponent much greater than 2, but that's apparently caused by the increased die temperature (according to the post on Anandtech).

static_noise 10y ago
That linked thread on Anandtech digs in quite a bit. The real physics involved is, of course, more complex than my simple model. Instead of a square dependence, they find the 5th power of the supply voltage. I believe this has to do with how the transistors are designed which creates a lot of wasted current at higher voltages. The square dependence would show with perfect transistors.