TDP and cooling system design

My m860tu came with a P9500 and a 9800m GT. That's somewhere around 90w, add a bit for ram, screen, and HDD and you're looking at about 110 watts. It can never draw more than what the 120w power brick can supply. When it's cranked up playing a game, the fan is really working to keep the temps under control, which typically hover just under 80C on the CPU and GPU.

Fast forward four years, and we have the P150EM with its 180w power brick, 100w GPU, and 45w Sandy/Ivy quads. That's a 50% increase in power consumption, but from the sounds of it, the temps aren't much higher than in my m860tu.

How? What advancement has allowed the same size chassis to dissipate 50% more heat energy? Computational thermodynamics? Advanced fan blade design? Witchcraft?

 

I guess for the Chip design... more power less heat?

 

Definitely witchcraft.

In all reality, it's generally due to the die shrink in processors. They typically use less power than older parts for the form factor. Anandtech says this about Ivy Bridge:

AnandTech - The Intel Ivy Bridge (Core i7 3770K) Review

Parts are more efficient, and with smaller surface area generating heat- it's easier to dissipate that heat.

Plus if I remember correctly, the m860tu only has a single heatsink/fan which is shared by the GPU and CPU, whereas most of the newer machines have two fans/heatsinks (one dedicated to each part).

 

That's what I missed.

Regardless of how much computing you can do per watt, you still need to get all that extra heat (60 more watts) out of the chassis. The advancement has apparently been that things have shrunken enough to fit a second fan where there wasn't enough room in the older machines. In fact, now that I've realized you have double the airflow but only 50% more heat to get rid of, I'm surprised they don't run cooler. I guess it's like anything else - adding fans is probably a game of diminishing returns.