Cooler Master Seidon 240M: Dual Fan Liquid CPU Cooler

Table of Contents

The Cooler Master Seidon 240M is a self-contained liquid CPU cooler with a dual fan radiator. Though equipped with a very quiet pump, its low noise performance doesn’t justify the US$100 price when compared to top air coolers.

February 25, 2013 by Lawrence Lee

Product
Cooler Master Seidon 240M
Liquid CPU Cooler
Manufacturer
Cooler Master
Street Price
US$100

Self-contained CPU water coolers provide PC enthusiasts with a no fuss, no
muss introduction into the world of liquid cooling. Putting together a kit yourself
can be more difficult than building an entire desktop system but these units
come pre-assembled for your convenience. They’re filled with coolant, sealed,
and pre-tested for leaks and other faults at the factory before being shipped
out; all you have to do is attach one end to the CPU socket and the other to
your case and you’re ready to go.



The Seidon 240M box.

The Seidon 240M is the newest member of Cooler Master’s watercooling line,
a premium US$100 model with a pair of 120 mm radiators. It ships in an
attractive purple box with gold text, a fitting choice as the two colors have
been associated with the upper class throughout much of human history. The interior
is lined with cardboard, molded to conform to the unusual shape of pre-assembled
water coolers. Tucked inside the other slots are two 120 mm fans, the mounting
hardware and an assembly guide.


Package contents.

Like other such units, the 240M has an unwieldy form, with a large dual fan
radiator at one side and a small round pump/waterblock at the other, connected
together with fairly rigid plastic tubing. Along with the necessary installation
gear are dampening pads to keep vibration down and a dual PWM fan adapter to
power both fans off the same header.

Cooler Master Seidon 240M: Specifications
(from the product
web page
)
CPU Socket Intel LGA 2011 / 1366 / 1156 / 1155 / 1150 / 775
AMD Socket FM2 / FM1 / AM3+ / AM3 / AM2+ / AM2
Pump Dimensions ø 70 x 27mm (ø 2.75 x 1.1 inch)
Radiator Dimensions 273 x 120 x 27 mm (10.7 x 4.7 x 1.1 inch)
Radiator Material Aluminum
Fan Dimension 120 x 120 x 25 mm (4.7 x 4.7 x 1 in)
Fan Speed 600~2400 RPM (PWM) ± 10%
Fan Airflow 19.17 ~ 86.15 CFM ± 10%
Fan Air Pressure 0.31 ~ 4.16 mm H2O ± 10%
Fan Life Expectancy 40,000 hours
Fan Noise Level (dB-A) 19 ~ 40 dBA
Fan Bearing Type Rifle bearing
Fan Connector 4-Pin
Fan Rated Voltage 12 VDC
Fan Rated Current 0.2 A
Fan Power Consumption 3.6 W
Pump Life Expectancy 70,000 hrs
Pump Noise Level <25 dBA
Pump Rated Voltage 12 VDC
Pump Load Current 0.15 A
Pump Power Consumption 1.8W
Warranty 2 years
UPC Code 884102020049

PHYSICAL DETAILS

The Cooler Master Seidon 240M (minus the fans) is composed of a 27.3 x 11.9 x 2.7 cm or 10.8 x 4.7 x 1.1 inch (L x W x H) radiator with 13 aluminum coils, two 30 cm long, 8 mm thick plastic hoses, and a 27 mm thick waterblock/pump with a large copper base. Altogether, the unit weighs 650 grams or 1.4 lb.


The heat dissipation cycle begins with a 51 mm diameter copper waterblock
clamped to the processor. The surface has a dull finish and a convex shape
like a shallow mound to ensure good contact with the center of the CPU
heatspreader. Coolant is circulated through this 27 mm thick structure
by the pump encased inside, and powered using a 3-pin fan cable.


The liquid travels through 30 cm of 8 mm thick hard plastic tubing to the radiator, transferring the heat to its aluminum coils. The fluid inside can be replaced through a cap but removing it voids the warranty.


The radiator is designed to mount to a dual 120 mm case fan position,
commonly found on the top panel of many tower style cases. The fans perform
the final step of the cycle, expelling the heat out of the system.


The radiator coils are an anemic 0.10 mm thick, curled into seemingly
endless rows that are easily damaged by light contact with any solid object.
This is stifling compared to traditional air-cooled heatsinks that have
long gaps between the fins.


The stock fan is a Blade Master, the same type used on many Cooler Master
heatsinks including the Hyper and GeminII series.

INSTALLATION

The most critical aspect of installation is that the heatsink be securely
mounted. A firm mating results in good contact between the heatsink’s base and
the CPU heatspreader and 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.


The mounting hardware is a stark contrast to water cooling units we’ve previously reviewed. Instead of plastic spacers and interlocking metal rings and hooks, there is just a simple bolt-thru backplate system.


For Intel boards, both backplate and mounting clips have easily adjustable
screws/bolts conforming to the various mounting hole arrangements of the
past few generations of Intel processors.


The mounting clips are screwed onto the base from the bottom which isn’t
ideal for maximizing pressure. We did notice some bending of the clips
after installation.


Thick steel nuts are fasted to the backplate screws using a conveniently included nut-driver.


The spring-loaded bolts are secured to the nuts and the base is successfully mounted. The base is fairly compact — one of the big advantages of watercooling is it bypasses most CPU heatsink height limitations. Unfortunately, the dual fan radiator makes it incompatible with most smaller cases.


The fans are bolted to the radiator side-by-side and the entire structure is screwed into the top of the case. The side with the tubing protrudes 19 mm past the edge of the fan while an additional 15 mm of clearance is required on the opposite side. For our usual open test platform we positioned the radiator about half an inch away from the top of the motherboard but we also arranged an in-system test as well.

TESTING

Before thermal testing, we took some basic physical measurements.

Approximate Physical Measurements
Weight
650 g (+160 g for each stock fan)
Height 27 mm (waterblock & pump)
Fin count N/A
Fin thickness
0.10 mm (coils)
Fin spacing
N/A
Vertical Clearance*
N/A
* measured from the motherboard PCB to
the bottom fin of the 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
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 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
Swiftech Polaris 120
0.43 mm
1.85 mm
Thermalright Venomous X
0.53 mm
1.84 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
Cogage TRUE Spirit 1366
0.40 mm
1.70 mm
Arctic Cooling Freezer Xtreme Rev.2
0.30 mm
1.70 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 are done on our
LGA1366 heatsink testing platform
, while smaller coolers tackle 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)

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
SPL@1m
Speed
12V
1250 RPM
28~29 dBA
9V
990 RPM
21 dBA
7V
770 RPM
15~16 dBA
6V
660 RPM
13 dBA

 

Reference Nexus 120mm fan
Anechoic chamber measurements
Voltage
SPL@1m
Speed
12V
1080 RPM
16 dBA
9V
890 RPM
13 dBA
7V
720 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 LGA1366 CPU heavily, generating more heat than most real applications.
    8 instances are used to ensure that all 4 cores (with Hyper-threading) are
    stressed.
  • 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 was off to ensure that system noise
did 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.

Noise Measurements

Specifications: Cooler Master Seidon 240M Stock Fan
Manufacturer
Power Rating
3.6 W (4.44 W according to label)
Model Number
A12025-24RB-4CP-F1
Airflow Rating
19.17 ~ 86.15 CFM
Bearing Type
Rifle
Speed Rating
600 ~ 2400 RPM
Corners
Open
Noise Rating
19 ~ 40 dBA
Frame Size
120 x 120 x 25 mm
Header Type
4-pin
Blade Diameter
113 mm
Starting Voltage
4.4 V
Hub Size
42 mm
Weight
160 g
Data in green cells provided by the manufacturer
or observed; data in the blue cells were measured.

The Seidon 240M ships with a pair of 120 mm PWM fans from Cooler Master’s Blade Master series; a similar model was used with the popular Hyper 212 Plus. This line has a unique twisted blade design, presumably to increase air pressure which is vital for cooling the densely packed radiator coils. It’s a high speed, seven blade model with curved struts and a very large hub that unfortunately eats up a sizable portion of the fan’s area.

Stock Fan Measurements
Voltage
Avg. Speed
SPL@1m
12V
2220 RPM
44 dBA
9V
1630 RPM
35 dBA
7V
1140 RPM
25 dBA
6V
880 RPM
19 dBA
5.5V
750 RPM
16~17 dBA
5V
460 RPM
12 dBA
Pump Measurements
12V
N/A
18 dBA
9V
17 dBA
7V
13~14 dBA
Measuring mic positioned 1m at diagonal angle from
the center of the cooler base.
Ambient noise level: 10~11 dBA.

The two fans we received were not perfectly matched, with a variance between
them of 50 to 80 RPM; the average nominal speed was just over 2200 RPM. The
pair were very noisy at top speed, emitting a strong buzzing and humming, both
of which dissipated as the speed dropped. They became bearable at ~ 1100 RPM,
and quiet at 900 RPM. The range of the fans is impressive, an earsplitting 44
dBA@1m at 12V to an almost inaudible 12 dBA@1m at 5V.

From a noise perspective, water cooling units have a significant weakness —
the pump that circulates the liquid through the loop. In the 240M, the pump
was actually fairly quiet, not exhibiting the harsh sounds we’ve encountered
in the past with similar coolers. It emitted a low frequency buzz with the occasional
slight rattle at 12V but generated only 18 dBA@1m. At 9V, the noise level dropped
by 1 dB, but subjectively it sounded worse as the pitch seemed to increase.
At 7V, it was barely audible.

Pump & Fan Measurements
Pump Voltage
Fan Voltage
SPL@1m
12V
6V
22 dBA
5.5V
20 dBA
5V
19 dBA
7V
6V
19 dBA
5.5V
17 dBA
5V
14 dBA
Measuring mic positioned 1m at diagonal angle from
the center of the cooler base.
Ambient noise level: 10~11 dBA.

At 7V and above, the fans produce so much noise they drown out the pump almost
completely, so undervolting the pump for silencing purposes only has an effect
when the fans are slowed down as well. Quiet levels are achievable with the
pump at full speed, but finding a balance between pump and fan noise rewards
the user with lower noise.

Test Results: Open Platform

Test Results: Cooler Master Seidon 240M
Fan Voltage
Avg. Fan Speed
SPL@1m
Thermal Rise
Pump at 12V
12V
2220 RPM
44 dBA
33°C
9V
1630 RPM
35 dBA
34°C
7V
1140 RPM
25 dBA
36°C
6V
880 RPM
22 dBA
39°C
5.5V
750 RPM
20 dBA
42°C
5V
460 RPM
19 dBA
53°C
Pump at 7V
12V
2220 RPM
44 dBA
36°C
9V
1630 RPM
35 dBA
37°C
7V
1140 RPM
25 dBA
38°C
6V
880 RPM
19 dBA
40°C
5.5V
750 RPM
17 dBA
43°C
5V
460 RPM
14 dBA
53°C
Measuring mic positioned 1m at diagonal angle from
the center of the heatsink.
Ambient noise level: 10~11 dBA.

We tested the pump at 12V and 7V with varying fan speeds in attempt to find
the perfect balance for our open CPU cooling testbed. At high fan voltages (7V
to 12V) the higher pump speed generated 2~3°C better cooling; the overall
noise levels were the same for both pump speeds as the fans drowned them out.
The lower pump speed only proved to be quieter when the fans were dropped to
6V and below. The performance-to-noise ratio was considerably stronger at the
slower pump speed.

High-End CPU Coolers (ref. 140mm fans):
CPU °C Rise Comparison
Heatsink
Fan Voltage / SPL*
7V / 15~17 dBA
6V / 12~14 dBA
Prolimatech Genesis
37
39
Thermalright HR-02 Macho
37
40
Noctua NH-C14
39
41
Thermalright Silver Arrow
39
41
Noctua NH-D14
40
42
Phanteks PH-TC14PE
41
43
NZXT Havik 140
40
43
SilverStone Heligon HE02
44
46
Cooler Master Seidon 240M (stock 120 mm fans, pump at 7V)
43 (5.5V)
53 (5V)
*Note: there are minor differences in measured SPL due to the variety of fan orientations and mounting methods offered by the compared coolers.

Given its US$100 price-tag, the Seidon 240M should be competitive with
high-end dual fan air coolers but it falls well short, at least at the noise
levels SPCR considers relevant. The cooling performance trails many such models
by double digits at the ultra quiet 12~14 dBA@1m level.

CPU Cooler Comparison (stock 120mm fans)
Cooler
Pump / Fan Voltage
SPL@1m
Thermal Rise
Antec Kühler H20 920
7V / 5.6V
19 dBA
41°C
Antec Kühler H20 620
7V / 6V
18~19 dBA
44°C
CM Seidon 240M
7V / 6V
19 dBA
40°C
7V / 5.5V
17 dBA
43°C
7V / 5V
14 dBA
53°C
Phanteks PH-TC12DX
N/A / 7V
23 dBA
42°C
N/A / 6V
18 dBA
44°C
N/A / 5V
14 dBA
47°C
Measuring mic positioned 1m at diagonal angle from
the center of the heatsink.
Ambient noise level: 10~11 dBA.

The Seidon 240M barely edges the Antec Kühler H20 920 we examined a couple
of years back. The 920, with its single fan on a very thick radiator, was bested
by only a single degree. Combing through our smaller heatsink reviews, we found
that the Phanteks
PH-TC12DX
equipped with a single stock 120 mm fan was the 240M’s closest
analog on our open testbed, except for a strong advantage at very low fan speeds.

There’s no point comparing the Seidon 240M to any of the top ranked air heatsinks
in our test database; they will clearly outperform the Seidon. The Phanteks
TC12DX is a solid heatsink hindered somewhat by poor fan performance. Still,
it’s a suitable choice to go up against the 240M in an in-case test.

IN-CASE TESTING

For our in-case test, we installed our LGA1366 CPU heatsink platform into an
Antec P280 case with the stock rear and front fans left in place and running
on low speed. The noise level of the system without the 240M running was just
14 dBA@1m so it had only a minor effect on the overall noise level. The 240M’s
radiator was secured to the case top panel with the fans blowing out, while
the Phanteks PH-TC12DX was mounted blowing to the side and the top fan mounts
left empty.

Our mic was placed one meter away from the side of the case at a diagonal,
so each cooler had the acoustic advantage of being placed further away (than
in free air testing) and a side panel blocking some of the sound.

Cooler Master Seidon 240M (pump at 7V)
Fan Voltage
Avg. Fan Speed
SPL@1m
Thermal Rise
6V
880 RPM
21~22 dBA
41°C
5.5V
750 RPM
18 dBA
44°C
5V
460 RPM
15 dBA
54°C
Phanteks PH-TC12DX (one stock 120mm fan)
7V
1100 RPM
18~19 dBA
45°C
6V
940 RPM
16 dBA
47°C
5V
750 RPM
15~16 dBA
50°C
Measuring mic positioned 1m at diagonal angle from
the center of the left side panel.
Ambient noise level: 10~11 dBA.

The Seidon 240M performed just as well in our open platform while the TC12DX
cooler took a 3°C hit across the board — the 240M had the obvious advantage
of being able to expel heat directly out the top of the case. However, tucked
inside the case, the overall noise from the Phanteks was reduced at both 7V
and 6V; the case obscured some of the noise it was producing. The noise level
of Seidon 240M, on the other hand, increased slightly when mounted in the case.
It would seem that the interaction between the radiator and the case, the metal-on-metal
contact (even with the dampening pads in place) and vertical orientation (compared
to the horizontal placement of our open testbed) made for a louder system.

These differences more or less canceled each other out, so the two coolers
were still closely comparable, with the exception of ultra-low airflow performance.
With each cooler’s fans at 5V, the Seidon 240M’s cooling proficiency fell apart,
while the TC12DX remained resilient. The bottom line is the 240M’s tightly wound
coils need higher airflow. It’s also important to note that the TC12DX was helped
along by only one rear case exhaust fan while the top two fan mounts were left
unoccupied, putting the Phanteks at somewhat of a disadvantage.

 

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 5~10 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.

  • Cooler Master Seidon 240M at 1m
    — pump at 7V, fans at 5V (14 dBA@1m)
    — pump at 7V, fans at 5.5V (17 dBA@1m)
    — pump at 7V, fans at 6V (19 dBA@1m)
    — pump at 7V, fans at 7V (25 dBA@1m)

FINAL THOUGHTS

The Cooler Master Seidon 240M is the best self-contained, CPU water cooling
unit we’ve tested, primarily because it addresses our biggest complaint about
such coolers: Pump noise. The previous integrated liquid coolers we’ve examined
from Corsair and Antec suffered from lousy sounding pumps that had a heavy buzz
and rattle, even gurgling on occasion, making them unfit for any true silent
PC enthusiast. The 240M’s pump is fairly innocuous by comparison, and it can
be undervolted to muted levels with little impact on cooling performance.

Despite this improvement over other watercoolers, the 240M fails to change
our general opinion of such devices. Liquid coolers may be well-suited for performance
enthusiasts who push their components to their limits and thus have to pair
them with high airflow, high noise coolers, but if you’re looking for quiet
cooling, traditional heatsinks remain superior. The 240M is an excellent performer
when fan speeds are cranked up but once you drop it down to quiet or near-inaudible
levels, its efficiency falls off considerably.

We expect a US$100 cooler to be lights-out, but the Seidon is barely
competitive with air cooled heatsinks that are half the price. It also takes
up fan positions that could otherwise be used for supplemental case fans. In
addition, the dual fan nature of the 240M negates one of best assets of water
coolers, the ability to fit in smaller cases with restrictive CPU heatsink height
requirements — most compact cases lack the necessary twin 120 mm fan mounts
to accommodate the 240M.

In our view, this type of cooling would be better applied to GPUs, as high-end
models produce considerably more heat than current CPUs, and the space on or
around a VGA card for a heavy duty heatsink simply doesn’t exist. For CPUs,
the only real usefulness of such watercoolers is to cool hot CPUs in small cases
without enough room for big air-only coolers. But the big radiator of the Seidon
240M makes it unsuitable for such a purpose.

Our thanks to Cooler Master
for the Seidon 240M CPU cooler sample.

* * *

SPCR Articles of Related Interest:

Phanteks PH-TC12DX CPU Cooler
Phanteks PH-TC90LS Mini Cooler
Thermalright TRUE Spirit 120M CPU Heatsink
Zalman CNPS9900DF Dual Fan Flower Heatsink
SilverStone Heligon HE02: Monster Fanless CPU Cooler
Antec Kühler H20 620 & 920 CPU Water Cooling Units

* * *

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this article in the SPCR forums.

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