Friday, February 3rd 2023
4 kg Literal Hunk of Copper Cools a Core i9 Processor
An 8 lbs (roughly 4 kg) solid cylinder made of copper was used as a fanless heatsink to cool an Intel Core i9 processor. This isn't a heatsink in that it's made of extruded copper, but a literal hunk of copper that is used as raw material. The metal is both extremely malleable and ductile, so it's shipped in such cylinders. The best part—the contraption is surprisingly good at the job, with That-Desktop-User, the Redditor behind this feat, claiming 35 °C idle and 80 °C load temperatures. The processor is essentially a heat-source that's trying to heat up the entire block of metal (with much lesser surface area for heat-dissipation than a real heatsink), which is how temperatures are being held at only up to 80 °C.
Source:
That Desktop User (Reddit)
64 Comments on 4 kg Literal Hunk of Copper Cools a Core i9 Processor
8.8 pounds on a cpu socket :cool:
Think he passed socket max pressure by a lot :laugh:
Board crushed as result.
The thermal conductivity of copper is 398 W/(m*K).
If we assume the ambient temperature is 20 C
If we assume the processor temperature is 80 C
Delta K = 80-20 = 60
We then have a cylinder, so surface area is 2*PI()*r*h+PI()*r^2 (one cylinder end removed due to interface with the CPU)
If the height is about 4", with the diameter 3" (This is the only way a "chunk" of copper would be 4 kg)
The surface area of the thing should be 2*PI()*1.5*4+PI()*1.5^2 = 44.76 inches square = 0.02888 meters square
Q = conductivity*delta T = 398 W/(m*K) * 60 K = 23880 W/m
0.02888*23880 = 689.65 Watts/material thickness -> gradient in Watts based upon geometry of cooler, with larger thicknesses meaning less conductivity
What? What does that even mean? Well, the amount of energy that we can transfer is least when we have the greatest mass of copper between the cooler and heat source, with the largest mass allowing significantly lower dissipation by virtue of a longer paths to transfer and material heat capacity. This also being balanced by inequality in delta temperatures due to not being at steady state temperature.
All of the above assumes conduction...with the ambient air basically being forced to move due to convection...which is not the same as convection heating. The funny bit is that as the hunk cooler heats up the convection effect would be stronger...but that's enough math to make my head hurt.
Short of it, this is a good cooler. It's also a stupid human trick, because 4 kg of copper is about 8.8 pounds of copper, and at about $22 per pound it's a $176 cooler. About $4 of copper can be constructed into heat pipes and fins, boxed, and sold for $40. You get the same performance by virtue of phase change energy transfer (water) and huge surface area...which is why we don't have solid state coolers in electronics...because if your average motherboard weighed 30 pounds nobody would want one.
It came from Reddit, they very easily could've called it a big chungus of copper :cry:
Indeed
Guessing they drilled the holes to save weight because 9lbs is way to much :laugh:
That's still quite heavy, just not as heavy as the one featured here.
Even my T-Rex pot is about 6.45lbs itself so yes, that's a heavy slug of copper.
Now let's turn this puppy 90 degree..
Also,
So just as any average 4090RTX. Cool.
Those holes are speed holes :cool:
heatsinks are for kids
Naked passive. Thanks Mother Nature!!