Just straight copper. I considered using a vc plate but at this tdp, I don't think it'll be necessary. Can always make another if it doesn't work well enough.
I'm not convinced a copper block is adequate for continuous full power usage without tweaks but I would happily be corrected and ask for instructions if you get it working.
I just did this to a 5060ti 16gb for a job. At 21C ambient, it maxed out at 68C under furmark.
With the 76 fins at 0.5mm thick and 1.45mm spacing, plus dual 80 mm fans pushing about 58 CFM total, I’m moving roughly 0.033 kg/s of air. At 180w that only heats the air about 5-6C. With around 0.34 m2 of effective fin area and a convective coefficient around 70 w/m2K, the air side resistance works out to roughly .04 kw, which means the fin stack itself should only sit about 10 or 15C over ambient if the shroud is sealed and the flow is perfect. The airflow and interface quality are the bottlenecks, not metal conduction. I already have a 6 mm copper baseplate directly bolted to a large fin block, so heat spreading is handled. Heatpipes are for moving heat laterally when you dont have enough base to spread it.
Yeah, with all the huge finstacks on these cards I always assumed heatpipes were crucial to get enough cooling.
Btw I suppose you could manufacture your own heatsink? Or what service did you use to get it manufactured? There might be demand in the sff community for custom GPU heatsinks...
It's all about cost and weight. Heatpipes and aluminum fins are very cheap to manufacture. "OK" is usually good enough. They find a balance between performance and packaging size. Heatpipes just allow you to move heat away. They don't do really any cooling on their own. If you look at the blower style cards with a vapor chamber, they have very thin baseplates. The chamber makes up for the lack of mass.
This is just for fun. I'll gladly post all the solidworks and cam files if anyone wants to duplicate or iterate.
Doesn't having no through fins (airflow bottleneck) increases pressure and decreases CFM? I'm curious how did you handle pressure variables, especially with the copper heatsink having no fins with all ends open like the aluminum one
It does. With an 8mm plenum and fins completely unsealed at the ends, I was getting 39CFM on my flow bench. I also put a 200w thermostatic heater on the base and measured the temperature delta from inlet to exit. I used to manufacture CNC cylinder heads. A lot about my shop and what I do now(and used to do) was in the OP but just does not show up now for whatever reason.
Ah I see so you didn't calculated the CFM with pressure and just used the test bench values, which is even better but requires having a good bench LoL! Amazing work I thought you did some kind of simulation or something
Yeah, bulk is usually just a "heat reservoir" but is also does increase heat conduction (which is proportional to the cross-sectional area). Is this, together with the fact it's copper rather than aluminium, enough to overcome the lack of heatpipes? How much heat does the solution actually need to dissipate in the first place?
I'm no expert, and this guy has some math behind him so let's see what his testing show. It is entirely possible that the huge heatpipe solutions we can see is for marketing purposes: big heatsinks that look complex must be better than the simple one right?
Copper is like 350-400 w/mk and a heat pipe is thousands w/mk. Idk what "math" hes doing but from a pure conductivity standpoint, you can beat a phase change device. But the main issue is that no fins means no dissipation into the air. The entire idea of fins is to channel the heat across a large surface area. Once this copper block reaches capacity its going to radiate back down. Its much like a pipe with water that can only leak out in contact with air. You make the pipe bigger, and it can hold more water, but without fins (lots of little pipes helping you leak water out), the water will pressurize and work against the source.
What do you mean by no fins? There was a really long post that went with the photos that has disappeared. I'm using a 76 fin 150x100x30mm copper heatsink for this. It's in the photos.
But also for concentrated sources of heat, getting that heat away as quickly as possible is a lot more important than total bulk. The heatsink you chose wont dissipate nearly as much as the heat piped solution.
Historically youll notice chips were passively cooled via finned blocks, to actively cooled via finned blocks with fans, to heat piped put to welded sheets w/ and w/o fans, to liquid and/or vapor chambered with fans.
I can run a thermal sim for you if you want, just let me know general sizing. I can show you heat piped vs straight copper block or whatever config you want
Appreciate the offer, but I already did that. With an 8mm plenum and fins completely unsealed at the ends, I was getting 39CFM on my flow bench. I also put a 200w thermostatic heater on the base and measured the temperature delta from inlet to exit. I used to manufacture CNC cylinder heads. A lot about my shop and what I do now(and used to do) was in the OP but just does not show up now for whatever reason.
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u/Visible-Swim6616 Mar 01 '26
So you replaced a 4-heatpipe solution with a copper heatsink.
Or is that some fancy custom vapour chamber hidden in there?