Noctua NH-D15: Update to an Icon

Table of Contents

The iconic Noctua NH-D14 helped usher in a new area of gigantic dual fan heatsinks. Its successor, the D15, is slightly heavier and larger, features upgraded matching 14/15 cm fans, and more densely packed fins.

May 30, 2014 by Lawrence Lee

Product
Noctua NH-D15
CPU Cooler
Manufacturer
Noctua
Street Price
US$90

The launch of the NH-D14 in late 2010 marked Noctua’s entrance into a newly burgeoning category of big CPU coolers. The D14 was one of the first models to feature a twin tower design, each with its own fan, working in conjunction to dissipate the heat pulled away from the CPU by the massive structure. Our initial testing proved its superiority, easily taking the top spot in our CPU cooling chart in 2011. Also contributing to its popularity was the easy to install and incredibly secure mounting system, the top-notch construction, and the well-stocked, best-in-class accessory kit. To this day, these qualities can be found in all their heatsinks, cementing Noctua’s reputation for not only manufacturing great cooling solutions, but for paying close attention to every detail of their products.

While it was a landmark cooler, the D14 has since been eclipsed by heatsinks from Prolimatech and Thermalright. Additionally, the upstart Phanteks, has been selling coolers with designs very similar to Noctua’s own, and their once revered rival, Scythe, has been experiencing a recent resurgence. Competition in this space seems to stiffen with each passing year and the market is now saturated with a host of competent competitors. To make matters worse, Noctua’s product cycle is much longer than most manufacturers, so the D14’s sequel has to get it right the first time and age gracefully to be successful.


The NH-D15.

The D15 is based on the same six heatpipe, dual tower premise as its predecessor but there are some notable differences. For one thing, the D14’s mismatched NF-P14 (140 mm) and NF-P12 (120 mm) fans, which caused unpleasant intermodulation effects, have been replaced with a pair of identical NF-A15’s, 150 x 140 mm fans equipped with their own dampening pads. The D14’s unnecessarily complicated fan clip mounting scheme has also been ditched in favor of a simpler but equally effective design that hooks directly into the fans’ mounting holes, as they should. The heatsink itself is slightly heavier and larger and its fins are stacked in a smaller, denser array. The tighter fin spacing increases interference, theoretically reducing low airflow performance, though presumably the upgraded fan can mitigate this possible shortcoming.


The box.


Boxes with in the box.


Accessories.

Noctua’s modus operandi of orderly packaging and including a useful set of accessories continues with the D15. The components are separated into individual boxes for the heatsink itself, the second fan, the Intel mounting hardware, the AMD mounting hardware, and a common set of extras. Included are a metallic case badge, a screw driver, a second set of fan clips, a pair of low noise fan adapters, and a Y-connector for running both fans off the same header. There are even soft and hard mounting gear for the second fan, just in case you decide to use it as a case fan instead — that level of consideration displayed is equal to none. The only thing that would make this a more complete package is the inclusion of some surplus mounting hardware in case a nut or spacer is misplaced. LGA2011 support has been added and while the mounting system remains the same, the included Intel backplate isn’t compatible with the older LGA775 and LGA1366 sockets. Users on these out-dated platforms are not left entirely in the cold though as they are eligible for a complimentary set of Noctua’s older NM-I3 mounting kit.

Noctua NH-D15: Specifications
(from the product
web page
)
Socket compatibility Intel LGA2011 (Square ILM), LGA1156, LGA1155, LGA1150 & AMD AM2, AM2+, AM3, AM3+, FM1, FM2, FM2+ (backplate required)
Height (without fan) 165 mm
Width (without fan) 150 mm
Depth (without fan) 135 mm
Height (with fan) 165 mm
Width (with fan) 150 mm
Depth (with fan) 161 mm
Weight (without fan) 1000 g
Weight (with fan) 1320 g
Material Copper (base and heat-pipes), aluminum (cooling fins), soldered joints & nickel plating
Fan compatibility 140x150x25 (with 120mm mounting holes), 140x140x25 (with 120mm mounting holes), 120x120x25
Scope of Delivery 2x NF-A15 PWM premium fan
2x Low-Noise Adaptor (L.N.A.)
Y-cable
NT-H1 high-grade thermal compound
SecuFirm2™ Mounting Kit
Noctua Metal Case-Badge
Warranty 6 Years
Fan Specifications
Model 2x Noctua NF-A15 PWM
Bearing SSO2
Max. Rotational Speed (+/- 10%) 1500 RPM
Max. Rotational Speed with L.N.A. (+/- 10%) 1200 RPM
Min. Rotational Speed (PWM) 300 RPM
Max. Airflow 140,2 m³/h
Max. Airflow with L.N.A. 115,5 m³/h
Max. Acoustical Noise 24,6 dB(A)
Max. Acoustical Noise with L.N.A. 19,2 dB(A)
Input Power 1,56 W
Voltage Range 12 V
MTBF > 150.000 h

PHYSICAL DETAILS

The NH-D15 shares a similar composition to its predecessor, with a copper base, 6 x 6 mm thick copper heatpipes, and 44 (rather than 42 for the D14) aluminum fins, all nickel-plated and soldered together. Curiously, its height is listed as 16.5 cm but our measurements peg it at 16.0 cm, the same as the D14, while its length and width of 15.0 and 13.5 cm respectively, match the specifications. The new behemoth weighs 990 grams according to our digital scale, equaling the SilverStone Heligon HE02, and heavier than the already substantial D14 by about 90 grams. The Thermalright HR-22 is the only more massive cooler we’ve reviewed in the past couple of years, weighing in at 1.17 kg.


Like the D14, the D15 is separated into two 50 mm thick towers. However, the two stacks are shorter, the bottom seven fins have been trimmed down, and there is greater clearance behind the center fan, about 8 mm.


Noctua has gradually phased out the distinctive waved edges of the D14 and its predecessors. The D15’s two towers have mostly straight contours.


The fin stack is shorter and more densely packed than the D14. While the D15’s fins are a tad thicker, measuring 0.46 mm, they are spaced closer together, 1.79 mm vs. 2.33 mm for the D14.


Noctua has used essentially the mounting system for years, with spring-loaded bolts pushing down on brackets attached above the base. This ensures sufficent pressure is exerted onto onto CPU.


The D15’s base appears to be more polished than previous Noctua models, but the finish is not quite mirror quality as the center is convex to ensure maximum comtact with the center of the CPU heatspreader. The manufacturing process leaves behind very fine machine marks on the surface.

INSTALLATION

The most critical aspect of installation is that the heatsink
be securely mounted as a firm mating results in good contact between the cooler’s
base and the CPU heatspreader, generating more efficient heat conduction. Ideally it
should also be a simple procedure with the user having to handle as few pieces
of hardware as possible. Noctua’s system is renowned for hitting all these marks.


The Intel backplate is similar to the U14S/U12S with fixed bolts for LGA115x motherboards only. LGA2011 is also supported but doesn’t require a backplate.


Simple to assemble and incredibly effective, the installation scheme is one of the best in the business. The backplate bolts go through the motherboard mounting holes from the back side, plastic spacers are slipped over them to get them to the proper height, and the mounting clips are attached with thumb-nuts. The spring-loaded bolts on the heatsink itself complete assembly.


The NH-D15 mounted on our LGA1366 test system, which required the use of an NM-I3 mounting kit repurposed from an older Noctua heatsink.


While the D15 is a huge heatsink, it’s actually dwarfed by the fan which covers a larger area. The fans sit very low, helping cooling the components around the CPU socket.


The heatsink stretched halfway over the Northbridge heatsink on our six slot motherboard. It may cause interference issues with seven slot models.


The D15’s size makes it impossible to avoid overhanging the memory slots. According to Noctua’s pictures, the fan should be mounted as low as possible, which makes it physically touch bare standard sized DDR3 DIMMs. Obviously you could place the fan higher to accommodate taller sticks but this would increase its overall height.


The D15’s thermal compound imprint reveals excellent contact at the center, indicated by the finer, fainter globules left behind. Less pressure is exerted at the sides, resulting in thicker residue around the edges.

TESTING

Before thermal testing, we took some basic physical measurements.

Approximate Physical Measurements
Weight
990 g (+160 g for each stock fan)
Height 160 mm
Fin count 44
Fin thickness
0.46 mm
Fin spacing
1.79 mm
Vertical Clearance*
54 mm
* measured from motherboard PCB to bottom
fin of heatsink

 

Large Heatsink Comparison:
Average Fin Thickness & Spacing
Heatsink
Fin Thickness
Fin Spacing
SilverStone Heligon HE02
0.52 mm
3.30 mm
Thermalright HR-01 Plus
0.45 mm
3.15 mm
Thermalright HR-02 Macho
0.34 mm
3.12 mm
Thermalright HR-22
0.53 mm
2.74 mm
Scythe Ninja 3
0.39 mm
2.64 mm
Noctua NH-U12P
0.44 mm
2.63 mm
Noctua NH-C12P
0.47 mm
2.54 mm
Noctua NH-D14
0.43 mm
2.33 mm
Thermalright Archon SB-E
0.49 mm
2.33 mm
GELID Tranquillo Rev.2
0.40 mm
2.30 mm
Phanteks PH-TC12DX
0.39 mm
2.30 mm
GELID GX-7 Rev.2
0.31 mm
2.25 mm
Phanteks PH-TC14PE
0.40 mm
2.21 mm
be quiet! Dark Rock 2
0.38 mm
2.22 mm
Prolimatech Armageddon
0.51 mm
2.08 mm
Prolimatech Megahalems
0.50 mm
2.00 mm
Zalman CNPS10X Quiet
0.40 mm
2.00 mm
Scythe Ashura
0.43 mm
1.97 mm
Scythe Kabuto & Zipang 2
0.34 mm
1.94 mm
NZXT Havik 140
0.41 mm
1.91 mm
Scythe Mugen-2
0.31 mm
1.89 mm
SilverStone Tundra TD03 (radiator)
0.43 mm
1.86 mm
Swiftech Polaris 120
0.43 mm
1.85 mm
SilverStone Argon AR01
0.30 mm
1.85 mm
Thermalright Venomous X
0.53 mm
1.84 mm
Scythe Mugen 4
0.30 mm
1.82 mm
Noctua NH-D15
0.46 mm
1.79 mm
Noctua NH-C14
0.38 mm
1.79 mm
Enermax ETS-T40
0.40 mm
1.79 mm
Scythe Yasya
0.32 mm
1.78 mm
be quiet! Shadow Rock Slim
0.42 mm
1.73 mm
SilverStone Argon AR03
0.42 mm
1.72 mm
Noctua NH-U14S
0.42 mm
1.72 mm
Cogage TRUE Spirit 1366
0.40 mm
1.70 mm
Arctic Cooling Freezer Xtreme Rev.2
0.30 mm
1.70 mm
Scythe Kotetsu
0.35 mm
1.66 mm
Scythe Grand Kama Cross
0.38 mm
1.66 mm
Reeven Kelveros
0.47 mm
1.61 mm
Zalman CNPS9900 MAX
0.16 mm
1.59 mm
Thermalright Silver Arrow
0.32 mm
1.57 mm
Cooler Master Hyper 212 Plus
0.43 mm
1.54 mm
Thermalright Ultra-120 eXtreme Rev.C
0.56 mm
1.52 mm
Zalman CNPS10X Extreme
0.42 mm
1.50 mm

Testing on larger heatsinks like this one is done on our
LGA1366 heatsink testing platform
, while smaller coolers are tested
on our LGA1155
heatsink testing platform
. A summary of the test system and procedure
follows.

Key Components in LGA1366 Heatsink Test Platform:

  • Intel Core i7-965 Extreme
    Nehalem core, LGA1366, 3.2GHz, 45nm, 130W TDP.
  • Asus
    P6X58D Premium
    ATX motherboard. X58 chipset.
  • Asus
    EAH3450 Silent
    graphics card.
  • Intel
    X25-M
    80GB 2.5″ solid-state drive. Chosen for silence.
  • 3GB QiMonda
    DDR3 memory. 3 x 1GB DDR3-1066 in triple channel.
  • Seasonic X-650 SS-650KM
    650W ATX power supply. This PSU is semi-passively cooled. At the power levels
    of our test platform, its fan does not spin.
  • Arctic Silver
    Lumière
    : Special fast-curing thermal interface material, designed
    specifically for test labs.
  • Noctua 140 mm fan (used when possible with heatsinks that fit 140x25mm
    fans)
  • Nexus 120 mm fan (used when possible with heatsinks that fit 120x25mm
    fans)
  • Nexus 92 mm fan (used when possible with heatsinks that fit 92x25mm
    fans)

Key Components in LGA1155 Heatsink Test Platform:

The systems are silent under the test conditions, except for the CPU cooling
fan(s).

Normally, our reference fans are used whenever possible, the measured details
of which are shown below.

Reference Noctua 140mm fan
Anechoic chamber measurements
Voltage
Speed
12V
1250 RPM
28~29 dBA
9V
990 RPM
21 dBA
8V
880 RPM
18 dBA
7V
770 RPM
15~16 dBA
6V
660 RPM
13 dBA

 

Reference Nexus 120 mm fan
Anechoic chamber measurements
Voltage
Speed
12V
1080 RPM
16 dBA
9V
880 RPM
13 dBA
7V
720 RPM
12 dBA

 

Reference Nexus 92 mm fan
Anechoic chamber measurements
Voltage
Speed
12V
1470 RPM
17 dBA
9V
1280 RPM
14 dBA
7V
1010 RPM
12 dBA

Measurement and Analysis Tools

  • Extech 380803 AC power analyzer / data logger for measuring AC system
    power.
  • Custom-built, four-channel variable DC power supply, used to regulate
    the fan speed during the test.
  • PC-based spectrum analyzer:
    SpectraPlus with ACO Pacific mic and M-Audio digital
    audio interfaces.
  • Anechoic chamber
    with ambient level of 11 dBA or lower
  • Various other tools for testing fans, as documented in our
    standard fan testing methodology
    .
  • SpeedFan,
    used to monitor the on-chip thermal sensors. The sensors are not calibrated,
    so results are not universally applicable. The hottest core reading is used.
  • Prime95,
    used to stress the CPU heavily, generating more heat than most real applications.
    All instances are used to ensure full stress.
  • CPU-Z,used to monitor the CPU speed to determine when overheating occurs.
  • Thermometers to measure the air temperature around the test platform
    and near the intake of the heatsink fan.

Noise measurements are made with the fans powered from the lab’s variable DC
power supply while the rest of the system is off to ensure that system noise
do not skew the measurements.

Load testing was accomplished using Prime95 to stress the processor, and the
graph function in SpeedFan was used to ensure that the load temperature is stable
for at least ten minutes. The temperature recorded is the highest single core
reading. The stock fans were tested at various voltages to represent a good
cross-section of airflow and noise performance.

The ambient conditions during testing were 10~11 dBA and 21~23°C.

STOCK FAN MEASUREMENTS

Specifications: Noctua NH-D15 Stock Fan
Manufacturer Noctua Power Rating 1.56 W
Model Number NF-A15 PWM Airflow Rating 140.2 m³/h
115.5 m³/h with L.N.A
Bearing Type SSO2 Speed Rating 1500 RPM
1200 RPM with L.N.A
Frame Size 150 x 140 x 25 mm (120 mm holes) Noise Rating 24.6 dBA
19.2 dBA with L.N.A
Hub Size 43 mm Header Type 4-pin PWM
Blade Diameter 133 mm Starting Voltage 4.5 ~ 5.0 V
Cable Length 20 cm Weight 160 g
Corner Type Open Retail Availability No

Additional notes:

The NH-D15 shares the same stock fan as the NH-U14S, both dubbed the “NF-A15 PWM.” Noctua sells a fan with the same model number but it’s a slower variant with a nominal rotational speed of 1200 RPM rather than 1500 RPM. Low noise adapters (L.N.A) are included, which bring the fan speed down to about 1200 RPM, but if you plan on using PWM, they can be better utilized elsewhere in your system.



The stock fan’s range according to Fan Xpert2. PWM control on the top top, DC control on the bottom.

According to ASUS Fan Xpert2, the stock fan can effectively operate at less than 200 RPM under PWM control. The threshold for voltage control is in the 700~800 RPM range, though we found that both fan samples could reliably start with slightly less than 5V (<700 RPM).

Stock Fan Measurements
Voltage
Speed
One Fan
Two Fans
12V
1480 RPM
31 dBA
33 dBA
9V
1190 RPM
25 dBA
27 dBA
7V
960 RPM
18~19 dBA
20~21 dBA
6V
840 RPM
16 dBA
17 dBA
5V
720 RPM
13 dBA
13~14 dBA
Measuring mic positioned 1m at diagonal angle from
the center of the heatsink.
Ambient noise level: 10~11 dBA.

Measuring 33 [email protected], the stock fans are quite loud at their top speed of ~1500 RPM. The low noise adapters effectively brings them down to 9V or ~1200 RPM, but they’re not particularly quiet at this level either; 7V adapters would’ve been better suited. The fans require a drop to about 900 RPM to hit the 20 [email protected] level and are barely audible near the bottom of their operating range on voltage control.

As we’ve stated in a past fan roundup and the NH-U14S review, the NF-A15 has an somewhat inferior sound to our reference NF-P14, and this is exacerbated in the NH-D15’s case as there are two of them. Each fan is buzzier than the reference model at higher speeds, and at 7V, develops some scratchiness. When paired up, they develop a steady mid-frequency hum that stands out at 7V and above. It’s not particularly unpleasant but noticeable compared to two NF-P14’s, which have a smoother acoustic profile with less tonality when producing equivalent noise levels. Otherwise, the sound produced is generally innocuous.

TEST RESULTS

Test Results: Noctua NH-D15
Fan Voltage
Single Fan
Dual Fan
Thermal Rise
12V
31 dBA
36°C
35°C
33 dBA
9V
25 dBA
37°C
36°C
27 dBA
7V
18~19 dBA
39°C
38°C
20~21 dBA
6V
16 dBA
41°C
39°C
17 dBA
5V
13 dBA
44°C
40°C
13~14 dBA
Reference 140 mm Fan (NF-P14)
12V
29~30 dBA
38°C
35°C
32 dBA
9V
22 dBA
40°C
36°C
24 dBA
8V
19 dBA
42°C
38°C
21 dBA
7V
15 dBA
43°C
39°C
17~18 dBA
6V
12 dBA
46°C
40°C
14 dBA
Measuring mic positioned 1m at diagonal angle from
the center of the heatsink.
Ambient noise level: 10~11 dBA.

The NH-D15 was an excellent cooler, generating a thermal rise above ambient of just 40°C at 5V and 35°C at 12V, a very tight range considering the varying noise levels generated. Single fan performance wasn’t much worse except when the fan voltage was lowered to 5V (720 RPM). Despite this, the noise reduction wasn’t great enough to make it more efficient overall. Replacing the NF-A15’s with our reference NF-P14’s produced nearly identical results, except in the one fan configuration, which greatly favored the NF-A15, especially at higher speeds.

HEATSINK COMPARISON TABLE

°C Rise Comparison: CPU Coolers with Single Stock Fan (Any Size)
20
19
18
17
16
15
14
13
12
11
Noctua NH-D15 (dual fan)
38
39
40
Scythe Kotetsu
38
41
42
Thermalright Archon SB-E
39
40
43
Thermalright HR-02 Macho
39
40
41
43
Scythe Mugen 4
40
42
45
Noctua NH-U14S
38
40
43
be quiet! Shadow Rock Slim
40
41
42
Noctua NH-D15
39
41

44

 

Scythe Yasya
40
43
Cogage TRUE Spirit 1366
41
43
46
Zalman CNPS10X Quiet
40
42
47
Scythe Ashura
42
44
Cooler Master Hyper 212 Plus
41
44
54
Silverstone Argon AR03
43
48
Scythe Ninja 3
44
46
SilverStone Argon AR01
44
50

The D15 compares favorably to competing coolers that ship with just a single stock fan, but only when both fans are utilized, and even then the margin is a slim one. With only the center fan, it slips down to seventh place.

°C Rise Comparison:
CPU Coolers with Dual 140 mm Reference Fans
Heatsink
Fan Voltage / SPL*
8V
(~20 dBA)
7V
(~16 dBA)
6V
(~13 dBA)
Prolimatech Genesis
36
37
39
Thermalright HR-02 Macho
36
37
40
Thermalright HR-22
37
38
39
Noctua NH-D15
38
39
40
Noctua NH-C14
37
39
41
Thermalright Silver Arrow
37
39
41
Noctua NH-U14S
39
39
40
Noctua NH-D14
38
40
42
Scythe Mugen 4
39
40
42
Phanteks PH-TC14PE
39
41
43
NZXT Havik 140
39
40
43
Scythe Ashura
40
41
43
SilverStone Heligon HE02
43
44
46
*Note: there are minor differences in measured SPL due to the variety of fan orientations and mounting methods offered by the compared coolers.

As a dual fan 140 mm fan cooler, the D15 rises near to the top, eclipsing the D14 as well as the Thermalright Silver Arrow and Phanteks PH-TC14PE, two coolers that also share a similar design. The Prolimatech Genesis remains the champion however, followed by the last two behemoths from Thermalright, the HR-22 and HR-02, but it’s a close race with only a degree or two separating the top six.

MP3 SOUND RECORDINGS

These recordings were made with a high
resolution, lab quality, digital recording system
inside SPCR’s
own 11 dBA ambient anechoic chamber
, then converted to LAME 128kbps
encoded MP3s. We’ve listened long and hard to ensure there is no audible degradation
from the original WAV files to these MP3s. They represent a quick snapshot of
what we heard during the review.

These recordings are intended to give you an idea of how the product sounds
in actual use — one meter is a reasonable typical distance between a computer
or computer component and your ear. The recording contains stretches of ambient
noise that you can use to judge the relative loudness of the subject. Be aware
that very quiet subjects may not be audible — if we couldn’t hear it from
one meter, chances are we couldn’t record it either!

The recording starts with 5 second segments of room ambiance, then the fan
at various levels. For the most realistic results, set the volume so that
the starting ambient level is just barely audible, then don’t change the volume
setting again.

FINAL THOUGHTS

The Noctua NH-D15 is the rare successor to a popular product that actually improves over every aspect of the original. It’s only a slightly better cooler than the D14, but has superior acoustics even though Noctua’s newer fan models aren’t as smooth sounding. This is due to having two fans of the same model rather than the D14’s odd 140+120 mm fan mix which never really made any sense to begin with. While it uses the essentially the same excellent heatsink mounting mechanism as its predecessor, the system of hooking the fan clips onto tiny plastic eyelets inserted into the fans’ mounting holes has been gleefully abandoned for a more traditional and simple method.

In the grand scheme of things however, the D15 does little to distinguish itself from its competitors. Similarly monstrous offerings from Prolimatech and Thermalright deliver equivalent or better dual fan performance. The D14 was the cream of the crop when it was released but dual tower heatsinks have since been eclipsed by thicker single tower designs. Noctua’s own older/smaller/cheaper heatsinks have held up fairly well, with the C14 being every bit the D15’s equal, and the sleek U14S doesn’t trail far behind either. The D15 is certainly better than the D14, but the rest of the field has improved as well. There are even a few much smaller coolers that stack of very favorably.

The Noctua NH-D15 is currently selling for US$90, which seems to be the standard rate these days for a flagship cooler. Given Noctua’s reputation and overall package, we don’t see them having a problem commanding this kind of premium, just as they have in the past. That being said, like many oversized coolers, you’ll need to look elsewhere if you want some semblance of value. If you can source a Scythe heatsink, the Mugen 4, and the Kotetsu in particular, offer much of the same performance for US$50 and less, even though they are armed just a single 120 mm fan. If you prefer the complete Noctua package, the older NH-C14 is a viable alternative as well, especially as it can be had for US$20~$30 less.

Our thanks to Noctua
for the NH-D15 CPU cooler sample.


Noctua NH-D15 is Recommended by SPCR

* * *

SPCR Articles of Related Interest:

Scythe Kotetsu CPU Cooler: A Compact King
be quiet! Shadow Rock Slim CPU Cooler
Thermalright HR-22 CPU Heatsink
Noctua NH-U14S Slim 140mm Tower Cooler
Scythe Ashura CPU Cooler
SilverStone Tundra TD03 Liquid CPU Cooler

* * *

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this article in the SPCR forums.

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