I was dismantling a computer to be recycled this morning, and I decided to remove the CPU heatsink on the off chance it would make a good paperweight. To my surprise, and near horror, I discovered that Gateway engineers in 2005 utilized a 600 gram block of extruded/milled aluminum bolted to the CPU as cooling. An ducted fan provided some extra convective cooling from the front of the case.
Although I have a great appreciation for the BTX form factor they used, from a thermal design standpoint, this thing is an atrocity. It relies on pure conduction to get heat from the CPU to the fins, and it also uses unpolished aluminum (< Cu). From a mechanical design standpoint, it's a giant waste of material because the aluminum block stretches a full 12.3 cm wide in order to provide support for mounting screws. All modern aftermarket CPU coolers use thin steel brackets to secure a tiny copper pad to the CPU surface. For reference, here's a stock Intel CPU cooler from 2012. This is as cheap as they come nowadays:
I removed the fan that was sitting on top of the heatsink so you could see inside. Although the fins are aluminum, the core of the heatsink is comprised of a copper vapor chamber (not a heatpipe). For the available surface area of the cooler, it’s incredibly efficient.
Any budding engineer who’s taken a basic heat transfer course shouldn’t be at all surprised by the newer designs, but I guess back when computer engineers were all like “herp derp, what do I do with this absurdly hot silicon,” this wasn’t such a clear answer.
I might continue to ramble about random engineering/science-y topics as the summer progresses… on the off chance I get bored building a dangerous slingshot…
BTW… Promising review of the AMD Athlon 64 3500+ from my dismantled computer:
"I also considered the 3200+, but figured I'd spend the extra $77 now and get the 3500+. Runs lightning fast! Runs cool. I'll never go back to Intel!"