Noctua’s DX line CPU coolers have become a default choice in premium grade quiet cooling solutions for Intel Xeon processors. The NH-D9 DX-3647 4U features a larger, custom-designed contact surface and supports both square and narrow type LGA3647 platforms. Based on the proven, 92mm size NH-D9L heatsink and equipped with two of Noctua’s award-winning, PWM controlled NF-A9 92mm fans (high-efficiency 2500rpm version), it combines strong performance with excellent compatibility for 4U systems and other space-restricted applications. Topped off with the professional SecuFirm2™ mounting system and pre-applied NT-H1 thermal compound, the NH-D9 DX-3647 4U forms a complete premium quality package for quietly cooling LGA3647 based Xeon workstations and servers.

Please note that the NH-D9 DX-3647 4U is a dedicated version for the Intel LGA3647 socket. Due to its customised larger base, it cannot be used on any other sockets and is incompatible with Noctua’s standard mounting kits.
DX series for Intel Xeon

DX series for Intel Xeon

First introduced in 2008, Noctua’s DX line CPU coolers have become a standard choice when it comes to quiet, premium grade air cooling solutions for Intel Xeon processors. Thanks to their superior acoustic efficiency, they are ideal for workstations and servers that run in noise sensitive environments (e.g. audio/video production, content creation, engineering, etc.).
Customised for LGA3647

Customised for LGA3647

The new DX-3647 line coolers are dedicated, customised solutions for Intel’s professional LGA3647 platform, which makes them an ideal fit for both Skylake-SP based Xeon Scalable CPUs (Platinum, Gold, Silver or Bronze, Purley series) and Xeon-Phi processors (code names Knight’s Landing or Knight’s Mill).
Enlarged contact surface

Enlarged contact surface

At 70x56mm, the heatsink’s copper contact surface is more than double the size of the standard model. Tailored to fit the enormous integrated heat-spreaders (IHS) of Intel’s LGA3647-based processors, this customised design allows for an optimal heat flow from the CPU over the base to the heatpipes and on to the cooling fins.
Supports square and narrow type LGA3647 sockets

Supports square and narrow type LGA3647 sockets

The heatsink’s SecuFirm2™ mounting system includes two sets of brackets in order to support both square and narrow type LGA3647 sockets. Thanks to pre-installed mounting screws and the included processor clips (square type and narrow type without Omni-Path fabric connector, with fabric connector on request), the installation procedure is easy, quick and secure.
Compact 92mm size for best compatibility

Compact 92mm size for best compatibility

Thanks to its compact footprint (95x95mm with center fan only, second fan can be installed on either side depending on available space) and a total height of only 134mm, the NH-D9 DX-3647 4U provides excellent PCIe compatibility and is small enough to fit most 4U size rack-mount enclosures.
Dual NF-A9 PWM fans

Dual NF-A9 PWM fans

The NH-D9 DX-3647 4U is equipped with two of Noctua’s award-winning NF-A9 92mm fans in their high-speed 2500rpm HS-PWM variant. This push/pull dual fan configuration makes it possible to achieve a level of cooling performance that is remarkable for such a compact cooler and comes close to the bigger NH-U12S DX-3647.
PWM support and y-cable

PWM support and y-cable

The NF-A9 premium fans supplied with the NH-D9 DX-3647 4U support PWM for convenient automatic speed control through the motherboard, which allows them to run near silent at lighter loads and to speed up only when necessary. The supplied y-cable makes it possible to power and control both fans simultaneously from a single motherboard fan header.
Pre-applied NT-H1 thermal compound

Pre-applied NT-H1 thermal compound

Noctua’s much-acclaimed NT-H1 is a pro-grade TIM solution that provides minimum thermal resistance and outstanding long-term stability. Having the paste pre-applied to the heatsink base ensures optimal bond-line thickness and saves precious time in installation. Ideal for system integrators!
6-year manufacturer’s warranty

6-year manufacturer’s warranty

Noctua products are renowned for their impeccable quality and outstanding longevity. True to this legacy, the NH-D9 DX-3647 4U heatsink is built to last, and like all Noctua fans, the supplied NF-A9 units feature an MTTF rating of more than 150,000 hours. The entire package comes with a full 6-year manufacturer’s warranty.
NH-D9 DX-3647 4U
Notes and warnings
Please note that the NH-D9 DX-3647 4U is a dedicated version for the Intel LGA3647 socket. Due to its customised larger base, it cannot be used on any other sockets and is incompatible with Noctua’s standard mounting kits.
Cooler Specification
Intel Xeon LGA3647
Height (without fan)
134 mm
Width (without fan)
95 mm
Depth (without fan)
95 mm
Weight (without fan)
584 g
Height (with fan)
134 mm
Width (with fan)
95 mm
Depth (with fan)
120 mm
Weight (with fan)
769 g
Copper (base and heat-pipes), aluminium (cooling fins), soldered joints & nickel plating
Fan compatibility
2x 92x92x25mm
Scope of delivery
  • 2x NF-A9 PWM premium fan
  • Y-split cable
  • NT-H1 high-grade thermal compound (pre-applied)
  • SecuFirm2™ mounting kit for LGA3647
  • Noctua metal case-badge
6 Years
FAN Specification
2x Noctua NF-A9 HS-PWM
Max. rotational speed (+/- 10%)
2500 RPM
Min. rotational speed (PWM, +/-20%)
400 RPM
Max. acoustical noise
30,6 dB(A)
Input power
1,68 W
Voltage range
12 V
> 150.000 h
NH-D9 DX-3647 4U
15.08.2018 // GreenTechReviews.ru

NH-D9 DX-3647 4U Review

Процессорные кулера Noctua NH-D9 DX-3647 4U являются уникальными в своём роде – при очень компактных размерах они демонстрируют отличную эффективность охлаждения большинства процессоров. Конечно, основное предназначение данных моделей – установка в 4U сервера, но никто не мешает их использовать и в Tower системах. При автоматическом управлении скоростью работы вентиляторов их слабо слышно, а если же установить максимальную – шум становится отчётливым, но в закрытом просторном корпусе это не будет проблемой, даже если он стоит рядом с вами. Тем более, что такой режим работы нужен с процессорами, обладающими TDP свыше 150 Вт. В остальных случаях кулера ведут себя очень тихо.
Test verdict: "В остальных случаях кулера ведут себя очень тихо. Качество, как и всегда, на высоте – придраться абсолютно не к чему. Кулера NH-D9 DX-3647 4U являются прекрасной заменой штатным очень шумным и гораздо менее эффективным решениям!" (Солонин Владимир, GreenTechReviews.ru)
24.07.2018 // XtremeSystems.org

NH-D9 DX-3647 4U Review

Noctua does it again. For people wanting to keep it simple, air cooling is about as simple as it gets. All three coolers from Noctua are very capable and allow flexibility for different case constraints. The combination of Noctua’s easy installation process plus top end performance makes the DX-3647 line of collers for LGA3647 platform an amazing choice for the first time builder or established enthusiast. You would be hard pressed to find a better tower cooler option in this range with this combination of performance, style, and operating noise levels. When you get to the point of making a choice on your cooling solution for your new LGA3647 platform, you really cannot go wrong with the DX-3647 Coolers. They have got enough technology built in to make your head spin, runs dead silent, looks great, fixes one of the greatest cooling challenges, and comes with a six-year warranty to make sure you are happy with your purchase in the long term. The suggested retail prices are as follows:
Test verdict: "Noctua does it again... You would be hard pressed to find a better tower cooler option in this range with this combination of performance, style, and operating noise levels." (Ambrosidou Nat, XtremeSystems.org)
04.07.2018 // Phoronix.com

NH-D9 DX-3647 4U Review

The SNK-P0068APS4 led to an average temperature of 31C at its full fan-speed while the Noctua NH-D9 DX-3647 4U had an average temperature of 23.5C with its fans at their full speed or 38.8C when using the automatic fan control enabled via the BIOS. The minimum and maximum core temperatures were also aligned with expectations. The Noctua heatsink did a nice job of allowing this Intel Xeon Silver CPU to run extremely cool inside this 4U chassis even at full load.
Test verdict: "From compiling the Linux kernel to running Python scripts to the many other workloads tested, the Noctua Xeon Scalable 4U heatsink was doing a great job at keeping the system running cool, especially at full-speed but even with the automatic fan control it was doing a great job. Even at full-speed, the NF-A9 fans were barely audible outside of the steel Rosewill 4U chassis, especially if you are running multiple systems in the room." (Michael Larabel, Phoronix.com)

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Installation Manual (PDF)

Information Sheet (PDF)

How should I clean my Noctua cooler?

Dust: Fans and heatsinks inside computer cases tend to accumulate dust over longer periods of usage. In order to maintain maximum performance, please clean your fan and heatsink regularly. For cleaning, please first remove the fan from the heatsink and clean it using a duster, slightly moist tissue or canned air. Please be careful not to use too much force in order to prevent any damage to the fan. Please do not use a vacuum cleaner as this may apply excessive force to the fan and do not put the fan under running water as water residues inside the motor may lead to short circuits. Please also note that the fan is not designed to be taken apart by the user. Removing the impeller from the frame will break the sealing of the bearing and results in a loss of warranty. Before reinstalling the fan, clean the heatsink itself with a duster or vacuum cleaner. Do not use water to clean the cooler. Finally put the fan back on and connect it to your motherboard fan header or fan controller.
Thermal paste residues: Whenever you take off the heatsink from the CPU, we recommend to clean the CPU as well as the base of the cooler before re-applying thermal paste and re-installing the cooler. You can either just wipe the base and the CPU clean with a dry, lint-free tissue or, for more thorough cleaning, use a lint-free tissue moistened with either a mild solution of washing-up liquid or isopropyl alcohol. Do not put the cooler or CPU under running water. Note that both the base of the heatsink and the CPU should be dry, free from residues of thermal compound and free from grease before re-applying thermal paste and re-installing the cooler.

How can I determine if the motherboard’s UEFI BIOS is overclocking my processor by default and deactivate this automatic overclocking?

Most motherboard vendors allow their overclocking-enabled products (e.g. those with Intels X- or Z-series chipsets) to run the processor at increased clock speeds by default, without requiring any user action at all. Since TDP (Thermal Design Power) limits are usually also disabled by default, this leads to the CPU exceeding the rated TDP to a varying degree, depending on the used applications and their workloads. Due to the increased heat output of the CPU, you may see higher CPU temperatures than expected.

In order to find out if your motherboard is overclocking your processor by default, please enter the UEFI BIOS and select the “advanced” or “overclocking” menu. There you should be able to find options such as “MultiCore Enhancement” (options: enabled/disabled), “CPU Ratio Apply Mode” (options: all/per core) or similar. To disable the automatic overclocking, adjust the settings either to “disabled” or “per core” and make sure that the individual multipliers match the original specifications.

In doubt, please contact your motherboard vendor for detailed instructions on how to disable this feature.

Which Noctua fan or CPU cooler should I buy? How to choose the right model?

Not sure which Noctua product to buy? Our detailed buying guides for fans and CPU coolers help you to choose the model that works best for you.

I have difficulties installing the cooler, can you help?

Please refer to the installation manual and our video installation guides for detailed instructions on how to install the cooler.

My case supports CPU coolers of up to XXXmm height, which model should I choose?

Please refer to our TDP guide in order to select the cooler that offers the best cooling performance at a given height.

I'm experiencing fan speed issues with my motherboard from Supermicro, what can I do?

The BIOS of many motherboard models from Supermicro expects a certain minimum fan speed (usually 600 or 700rpm), which is higher than the minimum fan speed that can be achieved with Noctua's PWM fan models. The BIOS may interpret the low minimum RPM of Noctua fans as a fan error and thus try to run the fan at 100% for a short period before going back to automatic control. This can result in oscillating fan speeds and fan speed warnings in the BIOS or the fan management console.

Unfortunately there is usually no option to set a lower minimum value in the BIOS that would suit the low minimum speed of Noctua PWM fans. The issue can thus only be resolved by either disabling automatic fan speed control in BIOS, which will cause the fans to run at a constant speed, by using 3rd party tools like IPMItool or IPMIutil, or by requesting a modified BIOS file from Supermicro, which takes the minimum fan speed of Noctua fans into account (charges might apply). Please note that any modifications performed with 3rd party tools are done at your own risk and that Noctua can not be held responsible for any possible issues.

Can I install a Noctua cooler in my system from Acer, Dell, HP or Lenovo?

Systems from Acer, Apple, Dell, HP, Lenovo or other major brands often use motherboards which differ slightly from the specifications issued by Intel and AMD. While those changes are usually subtle, they can lead to compatibility issues with coolers that were built to comply with these specifications.

Even in case the cooler is mechanically compatible and can be installed, other issues can occur, e.g. proprietary fan connectors, BIOS errors due to a low fan speed, shutdowns, etc. Some of these problems can be avoided with some technical knowledge, but especially BIOS related issues can often not be resolved.

Due to the large number of possible issues that cannot be resolved with different mounting parts alone, Noctua does not officially support systems from Acer, Apple, Dell, HP, Lenovo or other major brands.

What Thermal Design Power (TDP) is this cooler recommended for and how much Watt (W) of heat can it dissipate?

Please refer to our CPU compatibility list for information on maximum recommended TDP and heat dissipation.

Which sockets are supported or can be supported using upgrade kits?

Please refer to our socket compatibility chart.

Is it possible to use the cooler with vertical graphic cards?

Depending on the chassis, card and motherboard being used, installing PCIe cards in a vertical position using riser cards may cause compatibility issues with CPU coolers. Whether there will be a problem or not depends on the exact position of the card (which is determined by the PC case and/or optional vertical GPU holder bracket), the width of the card as well as the position of the CPU socket on the motherboard. In order to verify that there is sufficient space for the cooler, please measure the distance between the centre of the CPU socket and the top of the PCI card in order to make sure that the cooler fits.

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