You’re looking at about a half hour per kilogram of copper to raise it by 50 °C with 100W of heat.
Actual delta from ambient to thermal limit will typically be a little higher than that, but so is processor wattage on mid-to-high performance CPUs, so I’m happy enough with that as a ballpark estimate.
Someone else estimated that block as 4.5kg, so you’ve got something close to two and a half hours of cooling from an ambient start.
lead to problems
We’re talking about copper, dumdum.
Incredibly unwieldy. Real quick estimate of volume puts that at around 1.75kg of copper, so it wouldn’t be possible to mount in a vertical PC case orientation (ie the majority of consumer PC cases) without significant (expensive) modifications to both the mobo socket mount and the case, else its weight would snap the motherboard, or just slowly flex it until traces failed.
It may not even be able to be used vertically like that for very long or it will compress and damage the CPU / socket / mobo. Just as an example, the weight limit of the thermal solution (HSF/water chamber heatsink/etc) for socket LGA 1700 is 950g.
Real quick estimate of volume puts that at around 1.75kg of copper
I assume it’s at least ~5 cm × 5 cm × 15 cm. Given the mass density of copper 8.96 g/cm^3, its mass is at least 3.36 kg.
It begins with the question: How wide is the cpu?
Based on that, it’s approximately 3× as tall.
What’s a solid block of copper cost? one banana?
I have a micro ATX case that itself is the cooler. Heatpipes transport the heat to the case walls and they have fins to increase surface area. It can handle up to 65 watt CPUs.
It’s not produced anymore. But with all the talk of the Gabecube I’ve been itching to make a new build with it. Unfortunately I have neither the money or the energy.
Weight, cost, and it’s probably not effective for the long haul. The mass of a lead ingot like that will work like a heatsink, but it has a very low surface area for the energy it can absorb. So it’ll heat up to a point that is uncomfortable for the CPU, then fail to radiate that energy out to the air effectively.
As a test-bench temporary heatsink, this is actually kind of inspired. No fans, to fussy clips, just stack a copper brick on the CPU, run some benchmarks, and then turn it all off.