 There's a point where you can't make a cooler bigger because you can't move heat to the outermost fins fast enough for them to be helpful. So then, how the F does this work? I remember Noctua explaining to me that limitations of heat pipe cooling technology are the reason that they still have not updated the NH-D15, a design from over six years ago. So then does Ice Giant, who claims that this air cooler is competitive with custom water cooling, know something that Noctua doesn't? Actually, yes. But to explain, we're gonna need to have a look at the test results. Just like the test results I just got from my doctor. Looks like I've got a bad case of Segwayitis. Our sponsor, GlassWire, is the tool that shows you which apps are slowing down your connection. Used by security pros to monitor for malware, block bandwidth wasters, and detect suspicious activity, you can get 25% off today using offer code LINUS at the link below. When we showed off the Ice Giant ProSiphon prototype, it reached a level of insane cooling performance that we had never seen from an air cooler. But it did leave us with a couple of questions. One, was it good because of Ice Giant's thermosiphon technology? Or was it good because it had two high-speed Delta fans strapped to a heat sink big enough to bend the motherboard? Compared to their proof of concept, the production unit is much more reasonable. The ProSiphon Elite is equipped with much quieter fans and, well, it's still huge, but it is considerably smaller than the old version. The best part is that true to their promises, which we didn't quite believe at the time, this new version delivers the same performance as the prototype. Actually, it ended up being about half a degree cooler, while being smaller and much quieter. Apparently this improvement in efficiency is thanks to the third condenser unit that they added, which actually we should back up for a second and talk about the heart of the ProSiphon, the thermosiphon. Now we'll have more detail in our original video on the prototype, but here's the TLDR. Most modern air coolers work using heat pipes, which are super good at moving heat from one place to another, like thousands of times more conductive than copper. But heat pipes have a problem, dry out. Inside every heat pipe is a fluid that heats up and evaporates flowing away from the heat source, then condenses at the fins of the heat sink where the cooling is happening, and returns to the heat source using a wick. Heat pipe dry out occurs when the fluid starts boiling inside the wick that's supposed to be returning it to the heat source. This greatly increases the thermal resistance of the heat pipe and makes it really bad at its one job. Now for years, this didn't matter, since you need a lot of heat to cause dry out. Problem is nowadays, AMD's Threadripper 3000 series chips are rated at up to 280 Watts, and consume much more than that when you overclock them. So taming these beasts has been a challenge unless you want to move into custom water cooling. Now the way a thermosiphon works is somewhere in between a heat pipe and water cooling. Like a heat pipe, it boils a fluid at the heat source, but unlike a heat pipe, it uses some fancy engineering to turn the boiling fluid into a pump that circulates itself through the cooler. So you can kind of think of this thing as a wholly self-contained AIO, but way more reliable because there's no moving parts in here. The actual thermosiphon is expected to have a lifetime of decades, and that's backed up by a 10-year warranty. And unlike an AIO where the pump is expected to be the first thing to fail, the ProSiphon Elite's weakest link is its fans. The biggest quirk about thermosiphons though, is that because they use gravity to work, you can mount it like this or like this, but if you mount it like this, you're gonna have a really bad time. We're here for a good time though, so let's flip it around. Now normally the flow of air inside a case is pretty simple. Cold air comes in the front and then warm air is exhausted out the back, but in this case, pun intended, the rear fan is probably not doing a whole lot because of the way the ice giant exhausts its air upward. So in our testing with a Threadripper 3970X running at four gigahertz all core, our CPU temps dropped by four degrees by adding two fans to the top of the case. And we also found that having no rear fan at all didn't really change things. Taking the rear case fan out and chucking it in the top of your case could net you as much as three degrees with this cooler. One fun observation is that with Nvidia Founders Edition cards also moving to a more bottom to top airflow scheme, a pro siphon elite would probably pair well with one of those, that is, if you could find one. For our tests, our case fans were set to 1200 RPM and the CPU fans were set to maximum speed. We also monitored our room temperature and adjusted our results to 22 degrees ambient. Out of the gate on our Threadripper 3970X 32 core, this thing is shockingly good. It even handled our first overclock stage easily. With all 32 cores going at four gigahertz, the pro siphon elite reached a maximum temperature of 80.1 degrees and flew through our Blender Classroom render benchmark, which we had to run at 10 times the samples so that it would take 22 minutes instead of just two. Man, isn't Threadripper amazing? We then decided to give it all the beans and see just how far we could take this chip on the pro siphon elite. It turns out the weak link ended up being the silicon, not the cooling. The pro siphon was able to narrowly avoid thermal fraudling even when we pushed all 32 cores to 4.3 gigahertz at 1.37 volts. And for those of you who don't speak turbo nerd, these are the kinds of speeds that I would expect to need sub ambient cooling to achieve, not some roided out air cooler. This seems to be a limit of either our CPU or our motherboard, and I doubt additional cooling would make much of a difference unless we went really exotic. I mean, the poor motherboard VRMs were delivering over 250 amps during our 4.3 gigahertz run. What we don't know yet though, is if this great result is due to ice giants engineering or AMDs. So how do other Threadripper coolers stack up? To find out, we dusted off our trusty Noctua NH-U14S TR4. There are other options, notably the Cooler Master Wraithripper and the Thermalbright Silver Arrow TR4. But other reviews have shown the U14S to be both cooler and quieter. There's also the Arctic Freezer 50TR, which does slightly outperform the U14S, but RAM compatibility on that thing is atrocious. So it's off the table. NH-U14S then. Well, all I can say is it might need some sexy sweat bands. Lttstore.com, because this thing got hot. 13 degrees hotter to be exact. Dang. We also tested out the NZXT Kraken Z73, which predictably wasn't able to keep up. But really any cooler that's not specifically designed for Threadripper isn't going to be able to compete with one that is properly able to cover the entire IHS. And the reason is that the dies underneath are so spread out. Now we did have the Enermax Lictek TR4, but the pump died in our unit, which is apparently a common issue with these. So probably just avoid them, leaving us with only one other option, full custom water cooling. Now. It's not exactly a fair fight when you consider the cost. $170 for a ProSiphon Elite. That is really expensive for a cooler, but it's still less than half of this $440 of raw PC cooling goodness. And get this, the ProSiphon only lost by two degrees. What? One thing we haven't talked about yet though is noise. And with four fans, you might expect it to be pretty bad. In practice though, it's not. Even at full blast, they were barely able to crack the 42 decibel noise floor of our office, and there's no high pitched whining. So it's pretty easy to tune out, even though it is louder than Noctua's solution, which I would still recommend for stock operation. Bottom line then, if you've got a Threadripper computer, buy this, just buy it now. Assuming you can find anywhere to buy it. Who's carrying it? Okay then. But wait, minus there's like four minutes left in this video. Ah. Let's talk about the problem for Ice Giant. Most of you aren't made of fat stacks of cash, and you don't have a Threadripper system. And on any other platform, the U14S isn't Noctua's biggest baddest cooler. The NHD 15 is. So for our Intel cooling comparison, this is the only cooler we're going to test against, because frankly, if you want performance without going full custom liquid cooling, this is what you're buying. If you still need some convincing that it's better than an AIO, go watch this video. Installation on LGA 1200 is actually a little bit easier than Threadripper. Ice Giant appears to have taken our advice and basically just ripped off Noctua's Secufir mounting system. Now, since the point of this cooler is its ability to handle big heavy loads, we overclocked our Core i7-10875K to 4.9 gigahertz all core so that it would consume a tasty 230 watts, which the NHD 15 was able to handle without much issue. As for the ProSafe and Elite, well, it handled it, but worse. Five degrees worse to be exact. Now, it's still a solid result. The ProSiphon was able to take all 10 cores to the reasonable limit of our silicon, but there are a few things holding it back here. First and foremost, the ProSiphon Elite was optimized for multi-die designs like Threadripper and AM4, where the heat generation is spread out across the IHS. Intel consumer chips instead have a small heat generating die right in the center, and conventional heat pipe coolers, and AIOs for that matter, are designed to deal with this specific scenario. In the future, IceGiant thinks they'll be able to take on other coolers on more conventional chips, maybe by switching to a copper cold plate, but honestly, I doubt it would make a ton of sense to buy anyway. Most consumer chips are generating much less than 200 watts under normal circumstances, and that's where heat pipe coolers like the NH-U14 or D15 are still very efficient at scooting away heat. If you're using an Intel Extreme Edition, sure, the ProSiphon Elite Intel Edition could be a good buy. Can certainly generate enough heat for it, but we didn't bother testing that because frankly, no one should be buying an Intel Extreme Edition right now. Just get a 5900X or if you really need the threads, a Threadripper with one of these. Thank you to Ting Mobile for sponsoring today's video. Ting has new rates that make it easier to see how much you can save by switching to Ting. They've got unlimited talk and text for $10, data plans starting at just $15, and unlimited data for $45. So if you liked their previous pay what you use plans, don't worry, those are still there. They're just called Ting Flex plans charging just $5 per gig. Data can also be shared if you have a family plan, so you can connect more phones to save even more. You'll still get the same nationwide coverage and pretty much any phone will work with Ting. Just check them out at linus.ting.com and receive a $25 credit. If you guys enjoyed this video, maybe check out, you know what, go check out the video on the prototype because it gets into a little bit more of the sciencey stuff and it's worth a watch.