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Noctua NH-C12P: A Top-Down Cooler Rises Up

The first top-down CPU cooler from Noctua is a refined, unusual product that exudes thoughtfulness all around and comes with an equally unusual fan. But does it deliver silent cooling?

June 16, 2008 by Lawrence Lee

Product
Noctua NH-C12P
LGA775 & K8 CPU Cooler
Manufacturer
Noctua
Street Price
~US$65

It’s been a couple of years since we last reviewed the Noctua heatsinks, NH-U12 and NH-U9. Part of the reason for the long hiatus is that they haven’t changed much since those original models. Generally, we value longevity in an industry where most products seem to have a life span akin to the average ant — under six months. It suggests that the product was well designed to begin with. Noctua also made a name with its controversial, thin-bladed NF-S12 fan, designed for high airflow but not high pressure.

The NH-C12P is Noctua’s first down-blowing heatsink. Instead of exhausting
air towards the rear of a standard ATX case, it blows down toward the mainboard
and the voltage regulation circuitry around the CPU socket. The VRMs on modern
motherboards get very hot and on many models you will notice large heatsinks
on the MOSFETs. Cooling these components can help power efficiency as well increase
their life span. While it is hard to quantify the precise of benefit this additional
cooling, it certainly can’t hurt.

As before, the product is the result of collaboration between three entities: Kolink, a Taiwanese heatsink
manufacturer, Rascom, an Austrian distributor, and the “Austrian Institute of
Heat Transmission and Fan Technology”. A bit of marketingspeak: The name Noctua orginates from At hene noctua,
the scientific/Latin name for the little owl. The Greek goddess Athena and the
owl are synonymous in western civilization with wisdom.


The box. Noctua has an affinity for all things brown.

While great care may have been put into the heatsink’s construction, possibly
even more time and consideration has been put into the included fan. Most manufacturers,
with the noticeable exceptable of Scythe, usually don’t give fan selection much
serious thought. The NF-P12
fan
has been designed especially for use in high-impedance applications,
such as heatsinks. The “P” in the model name stands
for “pressure.” From the front of the box it looks like just another
fan, but don’t be fooled. Not only is it supposed to have unique properties, it is
also extravagently priced. The NF-P12 retails for more than US$20 on its own.


The provided mounting hardware is neatly separated.

 

Noctua NH-C12P: Key Features
(from the product
web page
)
Feature & Brief
Our Comment
6 heat pipes
6 heat pipes, excellently soldered joints and widely-spaced cooling fins
guarantee optimal heat dissipation even at low fan speeds.
These are 6mm in diameter. Soldered joints makes this heatsink somewhat unique; fins on most heatsinks are just press fitted onto the heatpipes.
CT C-type design with
Airflow-Gaps

Due to the down-facing design and two large Airflow-Gaps, the NH-C12P provides
additional cooling for near-socket motherboard components.
Top-down airflow provides
cooling for voltage regulation circuitry around the CPU socket.
NF-P12 NF-P12 120mm
fan

The award-winning NF-P12 has been specifically developed for high-impedance
applications such as CPU coolers. Thanks to psychoacoustic optimizations
and Noctua’s premium-grade SSO-bearing, the NF-P12 achieves exceptional
quietness and long-term stability.
The NF-P12 is designed
for high static pressure.
COMP Excellent compatibility
The down-facing c-type design allows for low height as well as excellent
motherboard and case compatibility.
At a height of 114mm
with the fan installed, it’s an easy fit in most cases.
SECUFIRM SecuFirm™
multi-socket mounting system

Noctua’s professional SecuFirm™ mounting system for LGA 775, AM2 and
AM2+ provides superior reliability and contact pressure. Xeon, Socket F
and K8 (939, 940, 754) kits are available on request.
Mounting system is 100%
metal. No plastic involved.
NT-H1 Noctua NT-H1 high-end
thermal compound

Noctua’s much-acclaimed NT-H1 is an pro-grade TIM solution that provides
minimum thermal resistance, excellent ease-of-use and outstanding long-term
stability.
For continuity, we won’t
be using their thermal compound. We’ll take their word for it.

 

Noctua NH-C12P: Specifications
(from the product
web page
)
Socket compatibility Intel Socket LGA 775, AMD
AM2 & AM2+, Intel Xeon on request, AMD K8 (754, 939, 940) & Socket
F on request
Height (with fan) 91mm (114mm)
Width (with fan) 126mm (126mm)
Depth (with fan) 152mm (152mm)
Weight (with fan) 550g (730g)
Material Copper (base and heat-pipes), aluminium
(cooling fins), soldered joints, nickel plated
Application Intel all frequencies, AMD all frequencies
Fan compatibility 120x120x25mm / 120x120x38mm
Scope of Delivery * NF-P12 premium fan
* Ultra-Low-Noise-Adaptor (U.L.N.A.)
* Low-Noise-Adaptor (L.N.A.)
* NT-H1 high-grade thermal compound
* SecuFirm™ mounting kits for LGA & AM2(+)
Warranty 6 Years
Fan Specifications
Model Noctua NF-P12
Bearing SSO-Bearing
Speed 1300 RPM ±10%
Speed w/ L.N.A. 1100 RPM ±10%
Speed w/ U.L.N.A. 900 RPM ±10%
Airflow 92.3 m³/h
Airflow w/ L.N.A. 78.5 m³/h
Airflow w/ U.L.N.A. 63.4 m³/h
Noise 19.8 dB(A)
Noise w/ L.N.A. 16.9 dB(A)
Noise w/ U.L.N.A. 12.6 dB(A)
Input Power 1.08 W
Voltage 12 V
MTBF >150,000 h

PHYSICAL DETAILS

The NH-C12P is essentially a “classic” design with C-shaped
cooler similar to most top-down heatsinks, but there are many unusual features.


The NH-C12P, sans fan.

With
its notched fins, the top of the heatsink resembles a bed of nails. From the
side they look like a row
of mechanical teeth. The ends of the heatpipes stick out in a slight curve
like a six-clawed paw or a series of spearpoints. Overall, the NH-C12P looks a bit
menacing, like it’s ready to do battle.


Notched fins.

While most of the fins have the dimensions of the end piece in the photo above, 15 fins are differently shaped, with the bottom portion extended in a trapezoid shape to connect directly to the base. The bottom of the fins look like they may be fitted into slots cut into the top of the base, and also soldered. These 15 fins naturally carry heat directly from the base. This is similar to the old Thermalright XP-120, which was one of the first heatsinks to employ heatpipes and very successful in its day.


Double-curved heatpipes for better clearance.

The main heat transfer path between the base and the fins are the six heatpipes, which are double-curved, like the ones on the recently reviewed Xigmatek
HDT-D1284
. The double curve is probably there to provide clearance for components around the CPU socket or memory sticks.

It’s easy to see the evidence of soldering at almost all the connecting points between parts. Show below is a closeup of two heatpipes as they enter the first fin. The traces of solder are visible all around the insertion point. Soldering should improve heat transfer.


Evidence of soldering.

The six heatpipes are evenly spread out through the fins, which allows each pipe
plenty of breathing room. Interestingly, the 15 fins that extend down to make direct contact with the base are not as wide as the others, which leaves a couple of gaps in the fin array. It’s a clever design: These gaps provide convenient screwdriver access for installation. It allows the heatsink to be mounted in any rotation, as dictated by the impediments on the particular socket 775 motherboard and case.


Top view: The holes in the fin array provide access to mounting screws.

Each layer has punched notches, creating a series of support flaps,
reinforcing the areas around the heatpipes. Structurally, it’s very stable
— it takes some force to bend or otherwise manipulate the fins. The rectangular holes also help reduce impedance to airflow.
The recently reviewed Thermalright
HR-01 Plus
has the same feature, but its “through-holes”
are much more numerous.


From underneath.


The NH-C12P base was flat and finished to a dull shine —
there were some very light machine marks. There was also some tarnishing
around the base and on the mounting plate, possibly a byproduct of the bonding
process.


The base.

INSTALLATION

The mounting system is vital to the performance of
any heatsink. Without proper mechanism for secure contact, the rest of the heatsink design is meaningless. We pay very close attention to the human interaction aspect of aftermarket heatsink design: People who are not necessarily PC hardware building experts have to install these things to get good use out of them. The installation process with the NH-C12P is a bit convoluted but not difficult, and it results in a secure, safely mounted heatsink on both AM2 and the more troublesome 775 socket boards.


Accessories. LGA775 mounting equipment on the lower left, AMD on the
lower right.

Along with the necessary mounting hardware, Noctua includes
rubber strips for soft fan-mounting, fan clips, thermal compound, and two
3-pin fan adapters for reduced fan speed, the Ultra-Low-Noise-Adaptor (U.L.N.A.) and the Low-Noise-Adaptor (L.N.A.). Both AMD and Intel installations
require four sets of hardware: A backplate for the underside of the motherboard,
mounting arms for the topside of the board, steel wings for the heatsink,
and spring-loaded bolts to secure it all together.


Socket 775 wings installed for the spring-loaded bolts. Note that the gaps in the fin array will be used to access these screws with a screwdriver.

 


LGA775 mounting arms attached. They could also have been mounted differently, across the path shown by the red lines, which rotates the heatsink 90 degrees. Which is the better way? It just depends on the details of your board. With AM2, the heatsink can only be mounted one way, dictated by the orientation of the heatsink retention bracket mounting on the board.

The backplate is placed on the underside of the motherboard,
and then washers placed over the four mounting holes to prevent short-circuits.
Mounting brackets are attached on the top side of the motherard via screws through to the backplate .


Installed. Note slanted fit of spring-loaded screws.

The holes on the wings attached to the heatsink attach to
the mounting arms and spring-loaded screws finish the job. They did not
appear to be perfectly aligned, ending up slightly crooked. It was
an extremely tight mating. Rotating the heatsink was impossible once it
was screwed on properly.

Postscript, June 17, 2008: A day after the review was posted, Noctua sent an email and explained that… “We’ve already modified the shape of the holes within the fastening brackets slightly to allow for a more convenient fit. You can also avoid the slanted fit of the spring-loaded screws by making sure that the mounting bars (on the motherboard) are pushed as close to the socket as possible during installation.”


Fan installed.

In the picture above the fan is not flush with the heatsink.
The fit was so tight that it could not be laid on top casually and actually
needed to be pushed down with some force to ensure proper contact. The fan
clips were also very tight.

TESTING

Noctua NH-C12Ps: SPCR Measurements
Weight 560 g (heatsink only)
600 g (heatsink, wings, and bolts)
780 g (heatsink, wings, bolts, fan and accessories)
Fin
thickness
~0.47
mm
Fin
spacing
~2.54
mm
Vertical
Clearance (northbridge)
~52
mm (measured from the PCB to the furthest reach of the heatsink)
Overhang (PSU) ~10 mm (This depends on the distance from the CPU socket to the edge
of the PCB.)

A comparison of fin thickness and spacing
among various tower heatsinks is interesting. The NH-C12P has the thickest fins
we’ve measured, and their spacing is moderate.

Comparison: Fin Thickness &
Spacing
Heatsink
Fin Thickness
Fin Spacing
Noctua NH-C12P
0.47 mm
2.54 mm
Thermalright HR-01 Plus
0.45 mm
3.15 mm
Thermalright Ultra-120
0.45 mm
1.42 mm
Xigmatek HDT-S1283
0.33 mm
1.96 mm
Scythe Ninja
0.31 mm
3.95 mm

Testing was done according to our
unique heatsink testing methodology
, and the reference fan was profiled
using our standard fan testing
methodology
. A quick summary of the components, tools, and procedures
follows below.

Key Components in Heatsink Test Platform:

  • Intel
    Pentium D 950
    Presler core. TDP of 130W; under our test load, it measures
    78W including efficiency losses in the VRMs.
  • ASUS
    P5LD2-VM
    motherboard. A basic microATX board with integrated graphics
    and plenty of room around the CPU socket.
  • Samsung MP0402H
    40GB 2.5″ notebook drive
  • 1
    GB stick of Corsair XMS2
    DDR2 memory.
  • FSP Zen 300W
    fanless power supply.
  • Arctic Silver
    Lumière
    : Special fast-curing thermal interface material, designed
    specifically for test labs.
  • Nexus 120 fan (part of our standard testing
    methodology; used when possible with heatsinks that fit 120x25mm fans)
Nexus 120 fan measurements
Voltage
Noise
RPM
12V
21 dBA@1m
1100 RPM
9V
18 dBA@1m
890 RPM
7V
16 dBA@1m
720 RPM
5V
<15 dBA@1m
530 RPM

Test Tools

  • Seasonic
    Power Angel
    for measuring AC power at the wall to ensure that the
    heat output remains consistent.
  • Custom-built, four-channel variable DC power supply,
    used to regulate the fan speed during the test.
  • Bruel & Kjaer (B&K) model 2203 Sound Level
    Meter
    . Used to accurately measure noise down to 20 dBA and below.
  • Various other tools for testing fans, as documented
    in our standard fan testing
    methodology
    .

Software Tools

  • SpeedFan
    4.32
    , used to monitor the on-chip thermal sensor. This sensor is not
    calibrated, so results are not universally applicable.
  • CPUBurn
    P6
    , used to stress the CPU heavily, generating more heat than most
    real applications. Two instances are used to ensure that both cores are stressed.
  • Throttlewatch
    2.01
    , used to monitor the throttling feature of the CPU to determine
    when overheating occurs.

Noise measurements were made with the fan powered from the lab’s variable DC
power supply while the rest of the system was off to ensure that system noise
did not skew the measurements.

Load testing was accomplished using CPUBurn to stress
the processor, and the graph function in SpeedFan was used to make sure that
the load temperature was stable for at least ten minutes. The stock fan was
tested at various voltages to represent a good cross-section of its airflow
and noise performance.

The ambient conditions during testing were 15 dBA and 21°C.



TEST RESULTS

1) Stock Fan

The fan included with the NH-C12P is the NF-P12. To maximize pressure,
the nine fan blades have less curvature than typical fans and there is very
little separation between them. This results in more noise, so Noctua
implements “vortex-control notches” designed to reduce turbulence and spread the noise generated
over a wider frequency range, making for a more pleasant sounding fan. A summary
of their claims can be read here
.

 

Brand Noctua Power Rating 0.09A
Model Number NF-P12 Airflow Rating 92,3 m³/h
Bearing Type SSO (Sleeve variant) RPM Rating 1300
Hub Size 1.61″ Noise Rating 19.8 dBA
Frame Size 120 x 120 x 25 mm Header Type 3-pin
Weight 170g Starting Voltage 4.8V

 

Noctua NF-P12 Measured Data
Voltage
Noise
RPM
12V
32-33 dBA@1m
1330 RPM
9V
22 dBA@1m
1060 RPM
7V
16 dBA@1m
840 RPM
5V
<15 dBA@1m
600 RPM

Fan @ 12V: The fan was fairly loud at 32-33 dBA@1m. It also throbbed with resonant
beats. Analysis of the acoustic profile revealed a tonal peak centered at 380Hz. The
throbbing, while less aggressive sounding than the normal buzz and whine common
to high speed fans, can be just as irritating.

Fan @ 9V: The fan became much quieter, registering only 22 dBA@1m. However, it
generated an unusual sound effect — that of an aircraft flying overhead. We
interrupted testing twice, believing that a plane was in the vicinity, but
it turned out to be the fan itself. We never thought a fan would be capable
of producing such a noise, but apparently it hit just the right frequency
and tone to create the effect. Spectrum analysis showed tonality around
360Hz with multiple harmonic overtones at lower amplitudes.

Fan @ 7V: The fan was almost silent and very smooth. Close-up it was still
audible, and the same airplane-type noise persisted though to a lesser degree.

Fan @ 5V: The fan was effectively silent.


Low-Noise-Adaptor on top, Ultra-Low-Noise-Adaptor on the bottom. Each appears to have an in-line zener diode to drop the voltage to the fan to about 9V and 7V.

 

2) Cooling Results

The NH-C12P showed itself to be an exceptional performer with
the stock Noctua NF-P12 fan. While unpleasantly loud at 12V, setting the fan
to 9V provided almost equal performance but with less than half the subjective noise. At
either voltage the thermal rise was well below 20°C, which is superb. 7V is probably the best trade-off between noise and performance.
At 16 dBA it is unlikely to be audible in most environments, and the 20°C temperature rise is excellent. Going to 5V provided very little acoustic benefit
and resulted in an additional 5°C increase in temperature.

Noctua NH-C12P w/ stock fan
Fan Voltage
Noise @1m
Temp
°C Rise
°C/W
12V
32-33 dBA
37°C
16
0.21
9V
22 dBA
38°C
17
0.22
7V
16 dBA
41°C
20
0.26
5V
<15 dBA
46°C
25
0.32
Load Temp: CPUBurn for ~10 mins.
°C Rise: Temperature rise above ambient (21°C) at load.
°C/W: based on the amount of heat dissipated by the CPU (measured
78W); lower is better.



FAN COMPARISON

We decided to pit
the NF-P12 fan against our reference Nexus fan and a Scythe Slip Stream
(800 RPM model). Whether it was at 12V, 9V, 7V, or 5V, the NF-P12 performed
within one degree of the Nexus fan. One degree is not enough to conclusive
say either fan is the winner; however, at 12V the Noctua fan was more than twice as loud as the Nexus. It was still louder at 9V, though the difference had shrunk to just 4 dBA.

The Scythe Slip Stream’s performance was similar, though it managed
to cooling slightly bettern than the other fans when they were all set to the same 16 dBA@1m noise level.

Fan Performance: NF-P12 vs. Nexus vs.
Scythe Slip Stream (L)
NF-P12
Nexus
Slip Stream (L)
SPL@1m
°C Rise
SPL@1m
°C Rise
SPL@1m
°C Rise
32-33 dBA
16
21 dBA
16
N/A
22 dBA
17
18 dBA
18
16 dBA
19
16 dBA
20
16 dBA
21
15 dBA
21
<15 dBA
25
<15 dBA
26
<15 dBA
24
Note: Slip Stream tested at 12V,
9V and 7V only.

These results suggest that….

  • The NH-C12P heatsink does not benefit from airflow any greater than that provided by the Nexus 120 at 12V.
  • The NF-P12 provides unnecessarily high airflow at 12V.
  • The NH-C12P heatsink is optimized for good performance with low airflow.

Hence, a much quieter stock fan could have been used. It’s possible that a much hotter CPU or otherwise more extreme thermal conditions could bring out the advantage of the expensive, high pressure NF-P12 fan.

HEATSINK COMPARISONS

Compared to other top-down coolers, the NH-C12P takes the crown
from the Scythe Andy,
beating it at all fan speeds except 12V by a small margin. It also easily outclasses
the more cumbersome Scythe
Zipang
.

Comparison: NH-C12P vs. Top-Downers
Scythe Zipang
Scythe Andy
Noctua NH-C12P
SPL@1m
°C Rise
SPL@1m
°C Rise
SPL@1m
°C Rise
23 dBA
18
21 dBA
16
21 dBA
16
18 dBA
20
18 dBA
20
18 dBA
18
16 dBA
25
16 dBA
23
16 dBA
21
<15 dBA
37
<15 dBA
29
<15 dBA
26
Note: Data for Andy and NH-C12P is
with a Nexus 120 fan; the Zipang was tested with its own 14cm fan.

 

Comparison: NH-C12P vs. Tower Heatsinks
Fan Voltage
Noise @1m
°C Rise
Xigmatek HDT-S1283
Ninja Copper
Noctua
NH-C12P
12V
21 dBA
13
17
16
9V
18 dBA
15
18
18
7V
16 dBA
18
20
21
5V
<15 dBA
22
23
26
The Nexus 120 fan was used for all the heatsinks.

Compared to the top tower heatsinks we’ve tested, the NH-C12P is about on
par with the Scythe Ninja
Copper
, and not too far from the the Xigmatek
HDT-S1283
. It is the first down-blowing CPU cooler to compare well against best tower coolers.



MP3 SOUND RECORDINGS

The recording begins with the ambient noise of the test
room. Please set your playback volume so that the ambient noise is almost inaudible,
then don’t adjust the volume control again. For best results, save the sound
file to your own PC, then listen.

Noctua NH-C12P with stock
NF-P12 fan at 5V, 7V, 9V and 12V at 1m
The recording starts with 5 seconds of the ambient in the room, then goes through 5 seconds at each of the four voltages.

Reference Comparatives

Nexus
“Real Silent 120mm fan”
(at 5V, 7V, 9V and 12V at 1m)

Scythe
Slip Stream SY1225SL12L
(at 5V-7V-8.4V-9V-12V at 1m)

Scythe
Andy Samurai Master w/stock fan
(at 5V, 7V, 9V and 12V at 1m)

Scythe
Zipang with stock DFS132512L 14cm fan
(at 7V, 9V, and 12V at 1m —
the fan was not recorded at 5V, because it was too close to the ambient.)

FINAL THOUGHTS

The Noctua NH-C12P proved to be the best top-down cooler we’ve tested.
It is also a formidable alternative to tower heatsinks, performing similarly to
the Scythe Ninja Copper. What is the reason for its success? It’s really the
whole package — the design is very well thought out. Great care was taken
into how the fins and heatpipes are shaped, bonded and spaced, and the mounting system
Noctua came up with is extremely secure. OK, it does require access to both sides of the motherboard, but for high performance cooling, this is mandatory even with heatsinks that use stock retention devices, because their sheer size makes them difficult to install with the motherboard inside the case. We applaud Noctua’s efforts. In comparison, push-pins
on other large, heavy heatsinks worry us not only about proper heatsink/CPU contact, but
also about long term mechanical security. About the only quibble might be that installation on an AM2 board can only be done one way, but this is much less of a concern that on blow-across, tower heatsinks.

The NF-P12 fan that ships with the heatsink is interesting.
Its notched blade design definitely alters the acoustic profile,
producing a unique sound. Whether it is more pleasant
than typical fans may come down to personal preference. All we can say is that
it definitely sounds different. Unfortunately, despite its “high
pressure” design, at maximum speed, it failed to provide better cooling on this heatsink than
our reference Nexus 120mm fan or a Scythe Slip Stream L. As mentioned earlier, the NH-C12P heatsink did not benefit at all from the high airflow or pressure of this fan. The saving grace is the inclusion of the speed-reducing in-line adapters, which obviates the need for other fan control devices and brings the noise level down to virtual silence.

The NH-C12P is currently retailing for around $65, a price inflated, no doubt, by the cost of
the included NF-P12 fan. This is about our only criticism of the Noctua NH-C12P. Other than the choice of stock fan, we can honestly say this is a great heatsink.

Noctua NH-C12P
PROS

* Top-notch performance
* Secure and easy to use mounting system
* Top-down cooling

CONS

* Very expensive
* Fan unnecessarily powerful

Our thanks to Noctua for the review sample.

* * *

Articles of Related Interest
Thermalright
HR-01 Plus: 2nd Gen Killer Tower Cooler

Scythe
Zipang 14cm fan “blow-down” CPU cooler

Cooler Master Hyper Z600
CPU Cooler: A Real Heavyweight

Intel’s HSF for high-end
Core 2 Extreme CPU cooler

Thermalright XP-120
Thermaltake MaxOrb Heatpipe
Cooler: Maximum Orbness


* * *

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