News Noctua's next-gen flagship CPU cooler finally arrives — Noctua NH-D15 G2 released at $150

[TheHerald]

Where do you think most of the video card heated air goes when using a tower cooler?

Video card cooler designs blow air out in every direction (or have flow through, but those dump hot air right into the CPU socket area) so the majority of the hot air will follow the flow of air in the case. That means most of the heat goes through the CPU socket area as that's where most of the airflow will be with a tower cooler.

With a proper airflow setup the disadvantage here is equal between an AIO and tower cooler. When using an AIO for exhaust you still want to try to have an overall front to back airflow path in the case rather than front to top (just talking standard case design front/top/back). That means setting up a fan curve that matches your workload or setting a low fixed RPM. The whole point of using liquid cooling (with reference to cooling advantage not aesthetic) is that you don't need to brute force anything you just need enough airflow that hot air doesn't stagnate.

The hot air going through the tower cooler has nothing to do with what causes the problem. The problem is that with a freaking radiator your total amount of air exhausted is less than it is with a tower cooler simply because you have restricted exhaust (due to placing a chunk of metal in front of it). Therefore the air temperature in your case will be a lot higher when using AIO vs an air cooler.

 

[thestryker]

Really now? You call other people failure and you don't understand what a freaking radiator does? A radiator placed into your exhaust reduces your airflow by as much as 1/3. Go check some fan reviews and see how much less air they push when put in front of a radiator.

Right because the fin stack on a tower cooler totally doesn't impact airflow, absolutely isn't the reason the best air coolers are dual tower, couldn't possibly be why push/pull configuration generally improves performance on single tower and definitely isn't why Deepcool has an option for a third fan on the Assassin IV.

The hot air going through the tower cooler has nothing to do with what causes the problem. The problem is that with a freaking radiator your total amount of air exhausted is less than it is with a tower cooler simply because you have restricted exhaust (due to placing a chunk of metal in front of it). Therefore the air temperature in your case will be a lot higher when using AIO vs an air cooler.

This is so astoundingly inaccurate it's almost funny. If you experienced this when using an AIO your airflow setup was very bad.

 

[TheHerald]

Right because the fin stack on a tower cooler totally doesn't impact airflow

Exactly, it doesn't. Putting a couch in your living room doesn't impact airflow as much as putting a couch right in front of your window. Try it.

This is a video measuring airflow unrestricted and through a radiator. It paints a very clear picture, airflow drops to half or even 1/3rd when you add a radiator.

Spoiler

View: https://www.youtube.com/watch?v=AeOvOeTbCrA

couldn't possibly be why push/pull configuration generally improves performance on single tower and definitely isn't why Deepcool has an option for a third fan on the Assassin IV.

Again, missing the point. Air going through the tower cooler is not the issue. The issue is that the total amount of air exhausted from your tower is drastically reduced when you are using a radiator. It's really, really, really not complicated. Putting multiple fans on a tower cooler doesn't change your case temperatures, just the CPU temperatures.

This is so astoundingly inaccurate it's almost funny. If you experienced this when using an AIO your airflow setup was very bad.

Of course my airflow setup was very bad, that's the whole point. It was bad because I had a huge chunk of metal blocking the exhaust. Switched to air cooler, 25c drop on the CPU, lol.

 

[TheHerald]

A tower cooler, in a tower case, is sitting in line with airflow from the intake fans. Some portion of its intake is going to be directly from that stream.

In contrast, a top-mounted radiator (I assume we're talking about like a 360 mm) is going to have 3 fans. That's probably more than doubling your number of exhaust fans and they'll be drawing air from wherever they can get it, including the GPU-heated air. So, if we hold the number of intake and dedicated exhaust fans constant (or replace some of the exhaust fans with the radiator), you just end up with a more heavily negative-pressure setup that will tend to pull air up from the GPU more.

It's very hard to argue hypotheticals, without going into specifics of different airflow setups, but I think @TheHerald has a point - and one backed up by personal experience. I'm not saying you can't do things to try and improve either configuration, but I think simply switching between a tower cooler and a top-mounted radiator, without changing anything else, will tend to work out as described.

The issue isn't that the radiator draws warm air from the GPU. The issue is your total amount of air moving out of the case is lower than with an air cooler cause your exhaust is restricted. That raises case temperatures drastically.

Igor's lab has tested this, most cases can't handle the heat generated from a 3090 or a 4090 even without an AIO restricting their exhaust. Now add an AIO to the mix and oh boy.

 

[thestryker]

Exactly, it doesn't

and with that I'm out because you clearly have no clue at all and this isn't worth my time

 

[TheHerald]

and with that I'm out because you clearly have no clue at all and this isn't worth my time

Clearly this is pidgeon chess. Proclaim yourself the winner and poop all over the board. Sure bud. I'm only figuring on top spots on every benchmarking chart but clearly, I have no clue. Whatever

 

[bit_user]

Really now? You call other people failure and you don't understand what a freaking radiator does?

I don't see where he said that. Let's calm down and try to understand your setup a little better.

A radiator placed into your exhaust reduces your airflow by as much as 1/3. Go check some fan reviews and see how much less air they push when put in front of a radiator.

So, you removed exhaust fans, in order to mount the radiator? I'm just trying to understand how many intake vs. exhaust fans you had with the AIO setup vs. the big air setup.

 

[bit_user]

What we need though is a standard that motherboard manufacturers can use too, so you can use any brand of fan without separate controllers. This shouldn't be too difficult either, the existing 4 pin fan layout should be usable still since the PWM pin is just a digital pin, just drive it like a PWM signal for PWM fans but then use it for a different protocol for other fans, like how you can change between DC and PWM on some motherboards.

Yeah, it's a shame ATX 3.0 missed out on things like that. That seems like it'd have been a fine occasion to do it. I'm also really disappointed they failed to add a standard mechanism for PSU telemetry.

 

[CmdrShepard]

I'm just curious how well that setup is working for anything that simultaneously stresses the CPU and GPU, such as gaming. Have you run anything on it, like that?

The case is big enough (Fractal Design Define 7 XL) and I have placed the GPU in the second PCI-e slot on the mainboard.

It seems to work well enough to avoid throttling, but then again I rarely play demanding games that can stress both CPU and GPU (I play at 1080p).

I can run Cyberpunk 2077 benchmark with everything maxed out if you want and let GPU-Z run in the background to monitor temps and power and then let you know.

EDIT: So the max temperatures for both CPU and GPU were 60-65 degrees. Note that the room temperature was 26 degrees though.

 

[bit_user]

The case is big enough (Fractal Design Define 7 XL) and I have placed the GPU in the second PCI-e slot on the mainboard.

It seems to work well enough to avoid throttling, but then again I rarely play demanding games that can stress both CPU and GPU (I play at 1080p).

I can run Cyberpunk 2077 benchmark with everything maxed out if you want and let GPU-Z run in the background to monitor temps and power and then let you know.

EDIT: So the max temperatures for both CPU and GPU were 60-65 degrees. Note that the room temperature was 26 degrees though.

Thanks for the info.

So, my last question (hopefully) is just to confirm which CPU you have. IIRC, it's something like a 12-core model that's based on the 24-core die. That relatively low thermal density seems like it should definitely help avoid the die -> IHS from being a thermal bottleneck. The large IHS, in turn, has an easier time getting heat into the heatsink, so you're not as dependent on a steep thermal gradient to help with that whole energy transfer.

 

[TheHerald]

I don't see where he said that. Let's calm down and try to understand your setup a little better.


So, you removed exhaust fans, in order to mount the radiator? I'm just trying to understand how many intake vs. exhaust fans you had with the AIO setup vs. the big air setup.

He said if you have higher temperatures with your aio you failed or something along those lines.

I was using a 280 aio as top exhaust on an o11. My 10900k was hitting 85 to 90c playing games after a prolonged amount of time (an hour or two) and the aio liquid temps were approaching 50c at times (which is a big nono btw).

Then I removed the aio, slapped 2x140 fans in its place and used a U12A on the cpu. Temperature dropped to 60-65c.

It's very self evident BTW, there are cases that don't have enough airflow to handle a big 400w gpu. Slapping a radiator into any case, even those with good air flows naturally restricts said airflow therfore it raises case temps. This shouldn't be up for discussion but somehow it is, lol

 

[bit_user]

I was using a 280 aio as top exhaust on an o11. My 10900k was hitting 85 to 90c playing games after a prolonged amount of time (an hour or two) and the aio liquid temps were approaching 50c at times (which is a big nono btw).

Then I removed the aio, slapped 2x140 fans in its place and used a U12A on the cpu. Temperature dropped to 60-65c.

Thanks for the info.

So, the case originally had no exhaust fans, other than the ones on the radiator? Did the case have an open back? How many & what size intake fans did it have?

 

[TheHerald]

Thanks for the info.

So, the case originally had no exhaust fans, other than the ones on the radiator? Did the case have an open back? How many & what size intake fans did it have?

The fans were the exact same with or without the AIO, nothing really changed. It had 3x120 side intake, 2x140 bottom intakes and the 2x140 exhausts on the top. That's how the case is supposed to be configured, i've tried multiple configurations and this worked best. Until of course I replaced my 250w GPU (1080ti) with a 3090, and then yeah, it was game over

But all of that is irrelevant to be honest. It stands to reason alone that any given case will have much higher airflow without a radiator then with one.

 

[vanadiel007]

If you're talking about gaming performance, then I think you're right.

However, for utilizing most of its multithreaded performance, you really need to get a CPU like the i9-14900K well above 125 W and that's going to take a lot more than the equivalent of a boxed cooler. Sure, Thermalright has some affordable options, but your cooler absolutely does matter.

Yes, I agree when it comes to Intel. Most others have advanced to a point where additional cooling brings little actual improvements.
Intel seems to be holding on to the "more power is faster computing" train of thought.

 

[TheHerald]

Yes, I agree when it comes to Intel. Most others have advanced to a point where additional cooling brings little actual improvements.
Intel seems to be holding on to the "more power is faster computing" train of thought.

Ιm scoring 41k with a 14900k on a u12a. How much performance would I be getting with additional cooling?

Please, just stop the nonsensical intel bashing. It got old, and it's not even freaking true in the first place.

 

[vanadiel007]

Ιm scoring 41k with a 14900k on a u12a. How much performance would I be getting with additional cooling?

Please, just stop the nonsensical intel bashing. It got old, and it's not even freaking true in the first place.

I don't know, how much more would you get?

 

[TheHerald]

I don't know, how much more would you get?

Around 1% at best, probably hitting 41500.

 

[bit_user]

The fans were the exact same with or without the AIO, nothing really changed. It had 3x120 side intake, 2x140 bottom intakes and the 2x140 exhausts on the top. That's how the case is supposed to be configured, i've tried multiple configurations and this worked best. Until of course I replaced my 250w GPU (1080ti) with a 3090, and then yeah, it was game over

So, the only exhaust path was through the radiator? Did you ever try adding a couple exhaust fans in the rear, or did the case just not have any support for that?

 

[TheHerald]

So, the only exhaust path was through the radiator? Did you ever try adding a couple exhaust fans in the rear, or did the case just not have any support for that?

The original o11 doesn't have any extra exhaust but I jury rigged a 90mm fan on the back ghetto style

 

[vanadiel007]

Around 1% at best, probably hitting 41500.

We see power consumptions so high that 360 radiator liquid cooling solutions are recommended to get the max out of it. +200 Watts of power consumption seems to be the standard as opposed to the 125 watt quoted power consumption.
https://www.tomshardware.com/features/intel-core-13900k-cooling-tested/2

That test determined 12% performance difference between "cheap cooling" and "strong liquid cooling". That's mostly because of the 125 Watt versus 300 Watt of power consumption when using high end liquid cooling.

You can look up the tests in that article, you will see I was correct when I said Intel seems to hold on to "higher power = more performance" mantra.

 

[Amdlova]

It's why I use a open chinese kit... my case has 55.000 liters of air... but still have two fans running at 600 rpm.

 

[NedSmelly]

It's not unusual for an over-engineered part to cost more, and it's definitely not limited to coolers.
Now that I'm more informed about it, the high price tag makes more sense to me.

I get the impression that this was never meant to be a mass appeal item - it's more of a 'halo' showcase product that shows off Noctua's design and manufacturing capabilities. So more of a PR statement.... as demonstrated by the GN deep dive.

It's like those artisan made outdoor tools. Beautifully crafted with the finest materials and manufacturing tolerances... but at the end of the day all you need to do is prune a shrub.

 

[TheHerald]

We see power consumptions so high that 360 radiator liquid cooling solutions are recommended to get the max out of it. +200 Watts of power consumption seems to be the standard as opposed to the 125 watt quoted power consumption.
https://www.tomshardware.com/features/intel-core-13900k-cooling-tested/2

That test determined 12% performance difference between "cheap cooling" and "strong liquid cooling". That's mostly because of the 125 Watt versus 300 Watt of power consumption when using high end liquid cooling.

You can look up the tests in that article, you will see I was correct when I said Intel seems to hold on to "higher power = more performance" mantra.

No you weren't correct. The AG620 is a cheap aircooler, compared to what at the time was the best AIO, the LT720. Performance delta between the 2? 2.5%, LOL.

Yeah, sure you were right bud.

Everyone holds to higher power = more performance mantra. What the heck do you even mean?

 

[35below0]

I get the impression that this was never meant to be a mass appeal item - it's more of a 'halo' showcase product that shows off Noctua's design and manufacturing capabilities. So more of a PR statement.... as demonstrated by the GN deep dive.

I'm not so sure. Noctua don't sell any cheap coolers. They do have cheaper models than the NH-D15 but even those are more expensive than rival coolers in that category.

I don't think they want to sell a cheap cooler.

 

[thestryker]

I'm not so sure. Noctua don't sell any cheap coolers. They do have cheaper models than the NH-D15 but even those are more expensive than rival coolers in that category.

I don't think they want to sell a cheap cooler.

Until the Peerless Assassin made a huge splash they didn't have any competition who undercut them by a lot. All of their competition was generally within 20% of their price for similar performance and quite frankly so long as the colors aren't a bother Noctua's fans alone are easily worth that price difference.

The current market is nothing like the market they released all of their coolers into. As it is their most recent non workstation/server coolers have all been cheaper models. I certainly don't expect Noctua to start making budget coolers, but there's no way they aren't aware of the market and set their sales expectations accordingly.