Noctua's pumpless 'thermosiphon' liquid cooling unit is expected to be released in 2026 and has already given me a free lesson in basic thermodynamics
Posted by SNad2020@reddit | hardware | View on Reddit | 122 comments
MaverickPT@reddit
Hope this comes to fruition at a reasonable cost. Have been fighting to quiet down my system and the pump on my Arctic LF3 can be one of the worst offenders if I ever let it go past 20% speed
Shedding_microfiber@reddit
In what orientation is the radiator? Is it higher than the pump?
MaverickPT@reddit
Frontal 360 rad with pipes at the bottom. Pump lower than the highest point of the rad.
FDrybob@reddit
I had a similar issue with my LFIII in my ITX build. I ultimately decided to switch to a Thermalright Peerless Assassin Mini instead, and that handled my 9800X3D with no problems.
TerribleQuestion4497@reddit
I am currently running Silent loop 3 and the pump on that is much better than LF3, you can still hear that signature annoying pump noise but it's much better than my LF3 was
MaverickPT@reddit
Funnily enough I had to rip out the P12's that came with my LF3 and replaced them with the silent wings 4 pros. Really happy with those fans
TerribleQuestion4497@reddit
Yeah, I had 420mm version of LF3 and first thing that got taken out were fans, they really don't have great noise profile and build quality, replaced them with a14x25 G2 and that's when I noticed the pump noise.
KTTalksTech@reddit
Oh wow that's unfortunate. On my cooler master 360mm (just their normal midrange line) the pump is at 90% constantly and I only hear it when putting my ear near the case
MaverickPT@reddit
To be fair to Arctic, if I recall correctly, although I'm not sure if that's the case, the pump on the LF3 is supposed to be stupid fast. So it gives you the choice of either slow and quiet or high/fast flow at the cost of noise. It's supposed to be one of the reasons why the LF3 performs well
bizude@reddit
Somehow, I don't see this working better than an air cooler.
Capable-Silver-7436@reddit
It's not always about better. Sometimes it's about different form factors
havoc1428@reddit
Then how is it effectively any better than a traditional AIO? I find the trade off of no-pump to be a net zero when faced by the fact the radiator must be placed above the CPU for this to work at all.
WorkReddit69@reddit
AIO tubing is permeable, and the liquid inside will lessen over time and since you can't fill (most) AIOs back up, you'll eventually have to replace it. The ones that can be refilled will eventually gunk up or the pump will die.
For me, no pump noise is the biggest selling point tho.
havoc1428@reddit
Do you honestly think this system won't off-gas over time? Its the same principle air conditioners use and even they need to be recharged after a time. You're also putting a ton of weight on the assumption that the constant phase changing of whatever liquid they put in this won't degrade overtime. I firmly believe this isn't as groundbreaking as people in this thread believe it to be because technology utilizing enthalpy of vaporization has existed for a very long time.
WorkReddit69@reddit
Not sure about Noctua's solution but the upcoming IceGiant 360 uses stainless steel tubing.
bphase@reddit
Why would that tradeoff matter if you were planning on putting it there anyway? Personally all I care about is performance, noise, reliability and value. And this is a way to get that reliability, potentially.
havoc1428@reddit
It wouldn't, but the person I replied to specifically state "form factors" and in this sense its a form factor that exists already, but has a limitation that the others do not.
dedoha@reddit
Knowing Noctua it will be 2c better than their top air cooler but will cost like $300
idontlikeredditusers@reddit
*sniffle* but will it be quieter i am willing to fork that money over if its 1db quieter
Frexxia@reddit
The ice giant cooler already exists, and proves you wrong.
bizude@reddit
I'd love to be proven wrong, their seems to be mixed opinions about their previously released products - I haven't tried them myself yet.
I've spoken to their representatives and will be testing the upcoming IceGiant Titan 360 - but at $420 USD, I would certainly expect impressive performance from it.
Berengal@reddit
IIRC from the old tests on the ice giant it performed the same as a decent air cooler until the power got really high. It didn't really make sense on anything but a threadripper. I fully expect that to still be the case as heat pipes are still just as effective at moving heat as a thermosiphon as long as they don't run dry and stall out.
Veastli@reddit
Yes, because it was specifically designed for Threadriiper and Epic.
If used on a standard desktop chip, about half the contact area of the IceGiant will not in contact with anything. Half the cooling potential is lost.
But when used on a Threadripper or Epyc, it outclasses every air cooler on the market, and not a few liquid coolers.
Berengal@reddit
It still had the same amount of contact on smaller CPUs. The issue was it used an aluminium cold plate which requires the heat to already be spread out more to get the same thermal conduction.
But all of that is beside the point as the tests I remember were done on threadripper CPUs. It didn't outclass anything else unless you added extra fans to it, which just comes down to the performance of the cooler is ultimately a function of the surface area of the fin-stack and the amount of air you're blowing over it.
The advantage of a thermosiphon over traditional heat pipe design is purely in how much liquid you can fill them with, which determines how much heat load it can handle before all the coolant evaporates. The mechanism of heat transport is the same.
Which brings us to the OOP comment: Does it work better than a traditional air cooler? Not as long as you stay within the performance limit of the heat pipes. It still functions within the same constraints, i.e. it needs to fit in a PC case without any flexible tubing, so any performance difference really just comes down the surface area of its fin-stack and the effectiveness of the fans.
VenditatioDelendaEst@reddit
Eh, I'm pretty sure thermosiphons can have the condenser farther away, because they aren't reliant on capillary action to transport the liquid phase, and can have higher throughput, because they don't have a sintered copper capillary matrix to obstruct the flow of the gas phase.
reddit_equals_censor@reddit
you have a condenser and an envaporator and a 2 phase system. you always condense liquid on top to run back.
why and how would all the liquid in a 2 phase thermosiphon evaporate?
and it doesn't make any sense based on the data, that shows thermosiphons scaling to the moon of course.
what? why. 360 mm top space for cases is common now, but of course we can also have 240 or 280 mm condenser versions.
and a sff build even build around a top aio would already fit the hardware, if the flexible metal tubes can be properly setup/thought of.
Veastli@reddit
IIRC, they tried copper and it didn't meaningfully improve cooling.
The larger point is that the ProSiphon was specifically designed for the larger, more spread out heat of Threadripper and Epyc.
It was not designed for the concentrated heat of standard Intel and AMD desktop CPUs.
All the criticism of the ProSiphon came from this mis-using it on standard desktop chips.
On Threadripper / Epyc, there is absolutely no air cooler able to match its performance, even with the stock fans. Upgrading the fans to something like the Phanteks T30-120 can improve cooling even more.
Veastli@reddit
You have been.
IceGiant's ProSiphon has been tested and proven to provide better performance than any air cooler on the market when used with the chips for which it was designed, Threadripper and Epyc.
Check the reviews.
bizude@reddit
I'll wait and see for myself. Like I said, I should be testing the IceGiant Titan 360 in the next few months.
Veastli@reddit
?? lol
The reviews have been published for years. There is nothing left to see. Their current product is absolutely, provably, superior to all rival air coolers, and not a few liquid coolers.
havoc1428@reddit
That is a thermosiphon system the relies on vaporization of the coolant which is literally no different from the heatpipes on an air-cooler. This Noctua cooler is a all liquid thermosiphon that doesn't undergo a phase change, the physics involved are different enough for a distinction here.
Frexxia@reddit
havoc1428@reddit
Yes? I said that. I literally said "This Noctua cooler is an all liquid thermosiphon that doesn't undergo a phase change"
Frexxia@reddit
Vaporization is literally a phase change
havoc1428@reddit
Okay, so I re-read the article and the linked article about the previous showing and I does look like it goes through a phase change. I was looking at those massive tubes and thinking "there is no way they are inducing a phase change in that much liquid unless its running hot" So I incorrectly pegged it as a old-school convection thermosiphon (Like an old car engine)
Thats what makes me draw doubts on this systems efficiency at anything but high-temps from systems like (for example) thread-ripper, where the delta between the radiator and source are high enough.
But you still need enough energy to induce a phase change, so the CPU still requires to run at an optimal temp (aka, hot). This is the reason why that Ice Giant cooler isn't shown to be any more effective than an regular aircooler on anything other than power hungry CPUs.
reddit_equals_censor@reddit
you are wrong.
the tower style ice giant thermosiphon prototype with a copper evaporator was tested by der8auer:
https://youtu.be/jPzclmc2dFY?feature=shared&t=469
on a dense heat desktop cpu the 12900ks it is on par or outperforms the best air coolers at the time.
it is worth remembering, that the first icegiant thermosiphon cooler having an aluminium evaporator was designed around threadripper, so dealing with very high heatdensity was not the goal, but it did fine enough, that they also just released it with mounting hardware for standard desktop setups.
so from looking at the der8auer test of the copper evaporator prototype, we are at least on par or better than the best air coolers, so the performance of a cooler with further improvmeents and 50% more surfance area in the condensor should be expected to be decently high.
so yeah you are missing quite a bit of context there and how design targets screwed with the outcome more than anything it seems.
Berengal@reddit
It works the same way heat pipes work, by reducing the pressure inside the system to where the liquid is already primed to evaporate with any extra input of heat.
The only difference is how the condensed liquid is returned to the cold plate, with traditional heat pipes using capillary action while a thermosiphon uses gravity. The advantage of the thermosiphon is that its volume of coolant isn't restricted by having to make the capillary action work, with the obvious downside that it only works in some orientations.
IIRC water is still common in heat pipes. The secret ingredient is the partial vacuum, not the coolant.
TwoCylToilet@reddit
Does the word "before" in "before vaporisation" mean nothing to you?
Frexxia@reddit
It means that the heat capacity of the liquid is high enough that it'll absorb a lot of heat before hitting its boiling point. Not that it doesn't boil at all.
havoc1428@reddit
To be fair, I got tripped up on that wording too when you quoted it, the rest of the paragraph puts it in context.
I'm curious what liquid they are using for this. It can't be just water because it wouldn't start to evaporate until it was literally at 100C.
AzN1337c0d3r@reddit
Heatpipes often use a combination of water and alcohol and below atmospheric pressure vacuum to lower the boiling point of the fluid into a better working range.
VenditatioDelendaEst@reddit
ORLY? I thought it was water only.
As far as I knew, mixed fluids in heatpipes are bad because whichever component is lower-boiling pretty much won't participate and just slows down vapor transport, and your materials have to be chemically inert with both fluids.
teutorix_aleria@reddit
I am not super familiar with the product but first review i looked up seems its more expensive and worse than the NH-D15 on both noise and thermals. So on par with mid range air coolers at triple the price.
SNad2020@reddit (OP)
I don’t either but this will be useful for those itx setups maybe
havoc1428@reddit
I would be very skeptical of that. Thermosiphon systems are very sensitive to factors like the temperature delta between the radiator and heat source. If people expect that radiator to be part of the chassis exhaust then they are going to be disappointed. The CPU will have to be at an elevated temp to create enough of a delta between it and the radiator. Notice how the Noctua display is essentially an open air bench, of course it works under ideal conditions.
einmaldrin_alleshin@reddit
As long as the boiling point of the fluid is sub-ambient, then the system would start working at any temperature delta, just like a heat pipe.
This wouldn't work with water, since air would inevitably diffuse into the system and raise the boiling point over time. But butane should work.
reddit_equals_censor@reddit
nope, not a problem. unless noctua lost it, it will follow the proper design for the eventual final real product and use flexible metal pipes and braced seals.
NO air getting in, just like no air is getting into a heatpipe, unless you get out your metal saw.
remember we have NO PUMP. i don't know the pressure, that the different setups for thermosiphons with flexible tubes are running at, but being sub ambient pressure is not a problem from my understanding at all.
but also water isn't used, but some stuff, that also inherently can't kill your electronics as well in general.
maybe a flexible metal tube changing the volume inside of the system based on bending could be an annoying variable, idk, but the point is, that seals are not a problem. air is NOT a problem. we use proper metal seals.
sealing stuff in isn't a problem if you just encase it all in metal :) i mean we got helium spinning rust as well :D although i guess not that rusty, as we got helium in those harddrives then...
reddit_equals_censor@reddit
people are already using thermosiphon coolers in pcs. the icegiant prosiphon elite is a thermosiphon in the form factor of an air cooler and it idles just fine based on the graphs we see from der8auer.
the cooler not working until x i haven't heard before at all for thermosiphon coolers.
well not the ones i looked at and got tested at least.
and that one is designed to be in a hot case.
the REAL issue for sff will be having flexible enough and right sized metal tubes for all to fight nicely together i guess.
COMPUTER1313@reddit
So it would have to be an intake only, especially if there's something like a RTX 5090 in the chassis.
Looks at the AM5 CPUs boosting until they hit 95C
I suppose if someone really wanted a silent build, they have to accept tradeoff somewhere.
reddit_equals_censor@reddit
the icegiant threadripper flexible metal tube version was shown at ces here:
https://www.youtube.com/shorts/F-yskKlK88c
cooling 660 watts of that 96 core threadripper cpu.
worth remembering, that less dense heat in server/threadripper chips is easier to deal with, none the less 660 watts handled is certainly impressive none the less.
and better than an air cooler is not the target.
on par with aios is the target with the reliability of an air cooler.
and we have performance tests done on the thermosiphon prototype with a copper evaporator and some other changes compared to the original, that has an air cooler like formfactor seen in this der8auer video:
https://youtu.be/jPzclmc2dFY?feature=shared&t=469
you can see it noise normalized performing slightly better/on par than the very best air coolers at the time.
add 50% more surfance area to the condensor with the flexible metal tube version and add further evaporator advances and it can deal with good aios, the ice giant titan 360 that is, that is the non threadripper version, the first link is the threadripper version.
so better than the best aircoolers is expected.
and we are assuming here, that the noctua cooler will be on par with the desktop icegiant flexible metal tube cooler (titan 360) , which is reasonable.
so yeah seems very promising tech and having flexible metal tubes and brazed connections is personally really exciting, because it means an unlimited lifetime and no more aio e-waste with a limited lifetime eventually.
cp5184@reddit
Depends what you mean by better, compare it to an aio with a broken pump...
labree0@reddit
Water coolers don't even work better than air coolers.
It's all for show
Extra-Advisor7354@reddit
Why don’t you tell that to all the data centers using liquid cooling?
labree0@reddit
yeah, because data centers are definitely going to be using noctuas new thermosiphon liquid cooling, arent they?
oh wait, they wont, and i obviously wasn't referring to an enterprise level solution with thousands of computers and heat distribution networks, where the conversation of "fan vs liquid cooling" kinda stops mattering when you can turn an entire room into an oven that could cook someone.
Extra-Advisor7354@reddit
If you don’t want people to point out your stupid comments, try not making stupid comments.
labree0@reddit
says the guy who started talking about data centers when we're clearly talking about personal computers.
Extra-Advisor7354@reddit
Keep on digging yourself deeper Timmy
beenoc@reddit
I mean, there's a difference between a gaming PC AIO (or even a custom loop) and a data center cooling system, in the same way that there's a difference between the 1800W Ryobi generator in my shed and a oil-burning power plant, or between a beer fridge in the garage and a 500hp industrial chiller. It's the same thermodynamics, but the scale and circumstances mean that it's not the same thing.
labree0@reddit
when i said they were only for show, i meant that they dont work better than air coolers.
I still dont actually believe an AIO is going to be better for a specific CPU, because at the end of the day all you are doing is moving heat away faster, but all of the components involved, assuming a static workload, are going to heat up eventually.
and outside of some really weird extenuating circumstances, SFF's are literally for show. people are almost never building SFF's because they have to fit their computer into some weird fucking place, its because they like the way it looks.
RuinousRubric@reddit
Air and water coolers are both ultimately heat exchangers. If one heat exchanger moves heat more quickly than another, then that means it can also move the same amount of heat with a lower temperature differential between the hot side and cold side. A computer cooler's hot side is the processor and the cold side is the ambient air, so a lower temperature differential means that the processor is closer to ambient (cooler).
Zenith251@reddit
Actually, there's already a huge difference between an AIO and a custom loop.
Not even comparable when dealing with high-output chips.
bizude@reddit
Uh, that's not quite true. They definitely work better than air coolers in some scenarios. I don't think it really matters much, but there are definitely benefits. For example:
If you're particular about CPU temperatures while gaming, an AIO will do much better than an air cooler. It doesn't really matter, but the temperature will be cooler.
If you're the type that wants to push every last watt through your CPU in a multi-core workload so you can be 0.1 seconds faster, liquid cooling is also useful.
A good AIO can let some CPUs run at their maximum turbo speeds indefinetly, whereas you'll see some thermal throttling with an air cooler. Of course this depends on the CPU you're using - it's basically pointless to liquid cool some CPUs (at least at stock settings) such as Intel's Core Ultra 7 265k!
labree0@reddit
im pretty sure linus had a video awhile back where they took the best coolers available at the time and pitted them against the best air coolers, and over time the water coolers stablized out to the same temperature. The only thing AIO's do better is pulling heat away immediately rather than waiting for the fans to catch up. At the end of the day, over extended workloads, they are both doing the exact same thing, and they'll both stabilize to the same temperatures, assuming both are using the same quality of hardware.
bizude@reddit
That doesn't match my experience in testing coolers, in periods of up to 30 minutes long. Were they testing in an open bench, or in an actual desktop case?
dedoha@reddit
Linus isn't the best source here, he has his personal bias against aio's and towards Noctua. I do agree however that water cooling isn't always needed and 6-8core cpu's difference will marginal but on hottest processors AIO can give over 10c lower temps
chefchef97@reddit
Is this the part where I leave a comment saying "I'll believe it when I see it"?
Jeffy299@reddit
I mean it's Noctua so I doubt it's a vaporware unless there have been dramatic changes at the company, but I doubt they were the first one with the idea. So I am bit skeptical it would be competitive against something like Liquid Freezer III with Noctua fans.
Strazdas1@reddit
Its Noctua, so its most likely vaporware just like most of Noctuas promises and roadmaps.
Zenith251@reddit
It's not that people think it's vaporware, but Noctua has been known to dump R&D into stuff then delay it for another year+, or just cancel it.
Rhoken@reddit
Maybe will be more competitive on the reliability aspect.
ritz_are_the_shitz@reddit
I mean, the Ice Giant thermosiphon was provably better than a tower cooler on CPUs that put out enough heat to cause heat pipe dry out.
Spyzilla@reddit
I always wanted to see this thing installed on a big GPU
Omotai@reddit
I think they mean the 2026 part.
COMPUTER1313@reddit
Add 5 years to all of their planned product launches and you won’t be disappointed.
TheFondler@reddit
Just 5?
COMPUTER1313@reddit
My apologies, I didn’t realize I was still optimistic.
chefchef97@reddit
You would indeed be correct
Though I guess you can factor in a 1-5% outside chance that the product fails their internal quality testing and gets shelved
namur17056@reddit
Is that the one Linus tried out a few years back?
Berengal@reddit
IIRC he did, yes, although it wasn't the final product at that point.
namur17056@reddit
Appreciate it knew I saw it somewhere before!
Dudi4PoLFr@reddit
"expected to be released in 2026" aka I'm expecting nothing on the shelfs before 2030.
imaginary_num6er@reddit
Could still be canceled like white fans
TrptJim@reddit
Also like active noise cancellation was quietly cancelled. 12 years since announcement. I was really excited for that.
DarkeyeMat@reddit
They silently killed the silent fans? That is ironiception.
Strazdas1@reddit
Invading dreams of irony?
klipseracer@reddit
At least they followed through to the end.
Sh1rvallah@reddit
I see you're quite the optimist
idontlikeredditusers@reddit
if this is gonna be in the middle of water cooling and air cooling with a better longevity might have to wait for it
SNad2020@reddit (OP)
I personally hope this is released soon at a reasonable price. The current AIOs already cost a lot of money and this alone would make me switch from my NH-D15
Gobeman1@reddit
Soon. They delayed the Desk fan by like 4-5 years
TerriersAreAdorable@reddit
Your NH-D15 is probably more effective than this cooler.
reddit_equals_censor@reddit
what noctua prototype you see above is a rough prototype, it doesn't even have proper seals or tubes yet.
so the question is rather how the final noctua version will perform, because who knows how the prototype will perform, if it is even functional.
SNad2020@reddit (OP)
Only thing stopping me from going sfx is my NH-D15 lol, otherwise an excellent product with no competition in terms of value
Tuuuuuuuuuuuube@reddit
The pa120 is 95% as good for 1/3 or less. The nh-d15 is completely overmatched from a value perspective, it's not really close
Stingray88@reddit
Don’t get me wrong, I love Noctua… but they don’t do either of those things.
reddit_equals_censor@reddit
they ONCE did.
the noctua nh-d14 was sold at a great price for the performance.
65/70 euro cooler, that was A LOT ahead of the competition back then.
that was a reasonable price.
a no brainer i'd even argue if you get a cooler back then.
but sadly no longer the case, or in a good way no longer the case? noctua increased prices, but competition caught up at much lower prices or vastly better value now i guess.
Churtlenater@reddit
Aren’t the Arctic AIOs like $100? I personally don’t think that’s bad at all especially considering they were twice as expensive and twice as unreliable a few years ago.
DeathDexoys@reddit
Nahhhhh, noctua doesn't do that
Gilaric@reddit
An Arctic AIO is just as expensive as a D15S
Acrobatic_Age6937@reddit
They'll charge double the NH-D15 price for this would be my guess. If there arent any constrains that block the usage of tower style coolers, then they are likely the best solution. Cheap, great performance, quiet, reliable.
nariofthewind@reddit
That thing has so many constraints that the only thing will ever hear about it is a quiet cancellation, Noctua style, of course.
Spirited-Guidance-91@reddit
so did they buy icegiant?
TheFondler@reddit
I think the biggest challenge with this is going to be orientation.
Contrary to what seems to be a popular belief, top mounted exhaust is not the best orientation for a CPU radiator when we have GPUs pumping 300-600W into the case. Radiators (and all heat exchangers) work through temperature gradients; the bigger the difference between the heated coolant and the cooling air, the more effective they are. If you are pumping heated air into your radiator, you are decreasing its effectiveness. You always want the coolest possible air going into your cooler.
This might work pretty well if you set fans as intake, but then you are creating some sub-optimal airflow and interior temperature scenarios inside the case.
VenditatioDelendaEst@reddit
Should be easy enough to fix with judicious application of ducts.
Rapogi@reddit
Ice giant has had the their thermosiphon out for quite some time now. The general consensus was that consumer cous aren't outputting enough heat to fully take advantage of the thermosiphon. To be fair the original ice giant was made for threadrippers and had adaptors/offset for regular cpus
So I'm curious how noctua is able to overcome this "problem." Maybe use of different type of liquid that evaporates at lower temps?
reddit_equals_censor@reddit
just use a copper evaporator for a start :D
the icegiant copper prototype, that der8auer tested already performed a small bit better or on par than the noctua nh-d15.
so yeah there seems to be lots of low hanging fruit to optimize for high heat density desktop chips.
Aleblanco1987@reddit
this is how many heating systems (with radiators) work since their invention.
Nvidiuh@reddit
I just want a black NF-A14X25 G2.
basement-thug@reddit
It's gonna take forever to reach steady state, and the initial temp spike is going to be too high for too long unless there's a massive amount of mass in the cold plate to absorb a lot of heat before it gets transferred to the fluid.
RandomGuy622170@reddit
If anyone can pull this off, it's definitely Noctua.
LickMyKnee@reddit
5% better for 300% of the price.
Frexxia@reddit
It would be unfortunate if there wasn't room in the market for products like that. I don't think Noctua is under any illusion that this isn't a niche product. Some people still want "the best" regardless of price.
Boo_Guy@reddit
I'd be interested in getting it largely because of Noctura's customer service.
If they weren't so great with their support after buying I'd probably stick with my D15.
I look forward to it's 2029 debut 😄
no_user_name_person@reddit
This a more efficient technology exists inside an air cooler. It’s called a heat pipe.
Frexxia@reddit
Thermosiphons and heat pipes are not the same thing
havoc1428@reddit
They literally are.
HelloItMeMort@reddit
This is literally just a long heat pipe with the ends connected. Or if it helps visualize, two heat pipes side by side, connected at the ends. One heat pipe focuses purely on sending vapor to the condenser, and one focuses purely on providing working liquid to the evaporator. A single heat pipe’s performance is constrained by having to ensure proper wicking of condensed vapor back to the evaporator, as well as a relatively small amount of liquid.
Jeffy299@reddit
I look forward to buying the 420 mm version in 2032
Pure-Huckleberry-484@reddit
If you had a variable speed pump you could test this with a loop easy enough - it won't be great...
unknown_nut@reddit
If successful, I want a 360/420 version.
gg06civicsi@reddit
This is how old cars used to implement liquid cooling. Good example is the Model T.
It’s probably not as effective at cooling as the alternative but might be ideal in certain scenarios.
savage_slurpie@reddit
So release date sometime in 2028 if we are lucky is what I’m gathering