New Passive Noctua Heatsink

Endgame

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Now here is a heatsink I’d like to see a review of:


I am completely not interested in fanless, but if it can cool a 3950 passively, I want to know what it can do with a 3000rpm Noctua industrial fan. Would it be better than the best active heat sinks, or are those actually better tuned for airflow?
 
Its probably more optimized for case flow and would benefit the most from a very well ventilated case is my guess.
Like server racks that have no fan on the HS but rather a good airflow right thru. (not quiet because of the insane fans they use).

Quiet will be the most priced asset for this cooler. High flow low rpm case fans etc.
 
This might catch your interest.

What would be really interesting is if they had taken a couple of big box fans and some cardboard and made a wind tunnel. Could they beat a high end custom loop? Then, even more (MOAR?!?) interesting would be to take that wind tunnel and put it outside. In Duluth. In January.

I’m not interested in passive cooling for silence - I’m interested in throwing fans on it and seeing how far it can be taken.
 
I’m not interested in passive cooling for silence - I’m interested in throwing fans on it and seeing how far it can be taken.
Going to hit diminishing returns at some point, right?

Noctua does list one of their 120mm fans as being compatible with the NH-P1. They have towers with two and three fan setups too.
 
Going to hit diminishing returns at some point, right?

Noctua does list one of their 120mm fans as being compatible with the NH-P1. They have towers with two and three fan setups too.
Yes, they have dual tower heat sinks with support for up the 3 fans, the largest being the D15.

My question: presuming I throw the same fan on them, which will yield better temps? The less expensive dual tower heat sink designed for active cooling, or the gigantic heat sink capable of passive cooling with a fan strapped on?
 
Yes, they have dual tower heat sinks with support for up the 3 fans, the largest being the D15.

My question: presuming I throw the same fan on them, which will yield better temps? The less expensive dual tower heat sink designed for active cooling, or the gigantic heat sink capable of passive cooling with a fan strapped on?
Given that cooling is always a function of mass, mass flow, differential temperatures, thermal properties, and surface area -- all other things equal that's a sucker bet.
 
Given that cooling is always a function of mass, mass flow, differential temperatures, thermal properties, and surface area -- all other things equal that's a sucker bet.
The D15 is certainly not a small heat sink, and There is no question that the D15 will get better airflow and is designed to have a fan strapped on. Even though it’s lighter, it may perform better given an airflow design optimized for a fan vs airflow optimized for convection.

unless that is what you were saying (I might be a little dense right now)
 
The D15 is certainly not a small heat sink, and There is no question that the D15 will get better airflow and is designed to have a fan strapped on. Even though it’s lighter, it may perform better given an airflow design optimized for a fan vs airflow optimized for convection.

unless that is what you were saying (I might be a little dense right now)
I think ... it depends. So thinking about it a bit more... maybe I should retract my sucker bet comment. I initially was thinking that more air will always yield better cooling, so the passive cooler was going to win hands down once you strap a fan to it. But after thinking through it a bit more here, I'm not so sure about that.

Your right - it's possible that a cooler with a smaller volume could cool better - because it may have more fins packed into a smaller area -- giving it more mass and surface area. Volume really only matters as it pertains to generating more surface area. The reasons HSFs have all those fins is just that - to give it more surface area for a given size (volume).

So - it depends. The one that weighs more will probably cool the best, to be honest, if you wanted just a rough thumb rule. That doesn't necessarily always apply, since you could have a really heavy baseplate or something... but for the most part, the more fins you have the more readily it will be able to reject heat... and with a fan you can pack those fins in more closely knowing that you have a fan pushing the air through. On a passive cooler you have to space them out a bit more or they will just get heat saturated and the channels aren't wide enough for the air to push - so you won't effectively transfer to the air that only has convection to drive it through the fins. And as you drive the mass flow (air flow) up - all HSFs will perform more efficiently, so more/faster fans will only help in all cases.

So if you have roughly the same base plate and mounting mechanism -- and most HSFs are going to be close in that regard -- the one with the most fins (surface area) is going to win, regardless. So the one that weighs more is probably going to carry. You can pack more fins in a smaller package if you know you have a fan to push, but I don't know how the mass / surface area difference will be with the passive monster cooler.

(I know - mass doesn't directly correlate to cooling capacity. Here I'm just using it as an easy proxy to get a relative comparison of number of fins... which will roughly correlate to surface area, and I'm making the assumption that the fins are made of roughly the same material and same thickness/guage. Mass does play a role, but it's more in how long it takes to hit saturation on a given cooling solution.)
 
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