Thermalright Venomous X Silent Edition CPU Cooler

The Venomous X Silent Edition is a combination of a potent Thermalright heatsink and a pair of extremely low speed fans. Though not completely “silent,” it is probably the quietest actively-cooled CPU heatsink available.

May 14, 2011 by Lawrence Lee

Product	Thermalright Venomous X Silent Edition CPU Cooler
Manufacturer	Thermalright
Street Price	US$70~$75

We’ve encountered many PC products over the years that have been described by its manufacturer as “silent” but as silence is defined as the complete lack of noise, most inevitably fall well short of the promise. Once you see a fan, at best it can be described as is “inaudible” or varying degrees of “quiet.” Present us with a “Silent Edition” CPU cooler with not one, but two fans, and we could suffer from a vertigo attack from the amount of eye-rolling required. That being said, Thermalright’s Venomous X Silent Edition might just have what it takes to be the quietest and most effective CPU heatsink to make this claim.

The package.

It is unclear how the retail version of the Silent Edition will be packaged. Though sold as a single unit, our sample arrived at our door in separate pieces, one unusually decorative box for the heatsink, one box for each 600 RPM fan just as they are sold in retail channels, and even individual cardboard containers for two plastic fan holders. The fan cages seem to a redundant inclusion as the heatsink ships with the traditional metal clips as well, which are superior in that they allow the use of 14 cm fans (provided they have 12 cm mounting holes). The Silent Edition also ships with a 4-pin PWM fan splitter cable to run both fans off the same header, though they are 3-pin models and thus lack PWM support.

Original Ultra-120 eXtreme on top, Venomous X on the bottom.

The Venomous X is not a new heatsink, having been made available in several forms for over a year. If you’re not familiar with it, it is very similar to the Ultra-120 eXtreme in design and composition. The overall dimensions are almost identical though the eXtreme is 5 mm wider as the center portion of the heatsink juts outward slightly. The shape of the fins on the Venomous X are also more stylized and its heatpipes are arranged in a different pattern.

Ultra-120 eXtreme on the left, Venomous X on the right.

The Venomous X also appears to have a larger fin-stack, but the total surface area is about the same. The spacing between the fins is wider than the eXtreme, which should improve performance with low speed fans like the 600 RPM models included with the Silent Edition. In addition there are twice as many of the small tabs on each fin that provide stability and ensure equal spacing.

Thermalright Venomous X Silent Edition: Key Features (from the product web page)
Feature & Brief	Our Comment
Patented multiple support pressure vault bracket system, allow users adding pressure to the bracket system (40~70 lbs. pressure system for Intel CPU user only), and have a more efficient and secure mounting.	The mounting system is critical for a heatsink’s performance.
Include AMD Socket AM2/AM3 Bracket system.	Sometimes omitted on CPU coolers.
Mirrored copper base increasingly upgrade the quality and the performance of the heatsink.	The base surface doesn’t need to be polished perfectly to perform well, but it’s a nice visual.
Special bent winglet design, allows hot air to pass the heatsink more rapidly.	A design element that debuted in the original Ultra-120.
Heatsink are all nickel plated to ensure the best quality and performance and could last for years.	Most high end heatsinks are nickel plated to prevent oxidation.
Soldered heatpipes, copper base and fins, to ensure the best thermal conducting efficiency.	Solder helps transfer heat between the various components of the cooler.
Six sintered heatpipe design, all heatpipes are nickel plated.To slow the oxidation deterioration to the heatpipe, to ensure longer usage and performance of the heatsink for the cpu.	Just like the Ultra-120 eXtreme, the Venomous X sports six heatpipes.
Including FDB 600RPM ultra low noise Fan Cover set*2 and Chill factor III thermal paste.	At 600 RPM, the included fans should be close to silent.
Convex copper base design, to ensure the Highest thermal conducting thermal efficiency between the CPU and the heatsink.	Like previous Thermalright heatsinks, the base is slightly convex to achieve greater contact with the center of the CPU.

 

Thermalright Venomous X Silent Edition: Specifications (from the product web page)
Heatsink
Size:	Length 127mm x Width 63mm x Height 160mm
Weight:	755 g (excluding fan and bracket system)
Heatpipe:	6mm sintered heatpipe *6 units
Copper base:	C1100 pure nickel plated copper base, with ultra-shine mirrored surface.
Fan
Dimension:	120*120*25mm
Bearing Type:	FDB (Fluid Dynamic Bearing)
Rated Voltage:	12.0 VDC
Operating Voltage Range:	10.8~13.2 VDC
Rated Current:	0.130 Amp +10% MAX /0.11AMP
Rated Power:	1.56 watt
Rated Speed:	600 RPM ± 10%
Airflow:	30.5 CFM
Noise Level:	13.1 dB/A
Life Expectancy:	60000 HOURS AT 40°c / 65%
Net weight:	156 GRAMS
Connector:	3 pin

PHYSICAL DETAILS & INSTALLATION

The Thermalright Venomous X Silent Edition is composed of a copper base, 6 x 6 mm thick copper heatpipes soldered to 47 aluminum fins, and the entire body is also nickel-plated. By our measurements, the heatsink weighs approximately 780 grams and stands 161 mm tall. The included mounting system is the same employed by the Thermalright Silver Arrow. The installation procedure is detailed here.

On average the fins are 0.53 mm thick and spaced 1.84 mm apart, an increase of more than 20% compared to the various editions of the Ultra-120 eXtreme.

Viewed from another angle.

The base of the Venomous X is convex and has a nice shine which is absent from some of Thermalright’s older coolers.

The mounting system employed is similar to that used by Prolimatech. Simple but effective, it features a bar at the center that exerts considerable pressure on the base.

Installed on our test motherboard with a pair of Nexus 120 mm fans. Note that if you use the wire clips, they should be installed before mounting the heatsink. The hooks are unusually long and may interfere with northbridge and VRM heatsinks.

TESTING

Before thermal testing, we took some basic physical measurements.

Approximate Physical Measurements
Weight	780 g 1110 g with stock fans and clips
Height	161 mm
Fin count	47
Fin thickness	0.52 mm
Fin spacing	1.85 mm
Vertical Clearance*	42 mm 33 mm with fan clips
Horizontal Overhang**	-19 mm -15 mm with fan clips
* measured from the motherboard PCB to the bottom fin of the heatsink. ** measured from the far edge of the heatsink to the top edge of the motherboard PCB.

 

Comparison: Approx. Average Fin Thickness & Spacing
Heatsink	Fin Thickness	Fin Spacing
Thermalright HR-01 Plus	0.45 mm	3.15 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
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
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
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
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
i7-1366 heatsink testing platform, while smaller coolers tackle our AM3 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 AM3 Heatsink Test Platform:

• AMD Athlon II X4 630 AM3,
  2.8GHz, 45nm, 95W TDP.
• Asus M4A785TD-V EVO ATX motherboard.
  785G chipset.
• Kingston
  SSDNow V 30GB 2.5″ solid-state drive. Chosen for silence.
• 2GB
  Corsair Dominator DDR3 memory. 2 x 1GB DDR3-1800 in dual channel.
• FSP Zen 300W
  ATX power supply. Fanless.
• 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	28~29 dBA	1250 RPM
9V	21 dBA	990 RPM
7V	15~16 dBA	770 RPM
6V	13 dBA	660 RPM

 

Reference Nexus 120mm fan Anechoic chamber measurements
Voltage	SPL@1m	Speed
12V	16 dBA	1100 RPM
9V	13 dBA	890 RPM
7V	12 dBA	720 RPM

 

Reference Nexus 92 mm fan Anechoic chamber measurements
Voltage	SPL@1m	Speed
12V	16 dBA	1470 RPM
9V	12 dBA	1150 RPM

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 Burn,
  used to stress the AM3 CPU heavily, generating more heat than most real applications.
  4 instances are used to ensure that all 4 cores 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 or CPUBurn 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

The fans included with the Venomous X Silent Edition use fluid bearings and spin at just 600 RPM. They have a standard seven blade design with gentle curves and straight struts. They weight about 160 grams, which is 40 grams more than most 12 cm models. Much of the extra weight is probably due to the motor as the hub measures an unusually wide 47 mm across.

Specifications: Thermalright Venomous X Silent Edition Stock Fan
Manufacturer	Thermalright	Power Rating	1.56 W
Model Number	TR-FDB-12-600	Airflow Rating	30.5 CFM
Bearing Type	Fluid Dynamic	Speed Rating	600 RPM ± 10%
Corners	Open	Noise Rating	13.1 dBA
Frame Size	120 x 120 x 25 mm	Header Type	3-pin
Fan Blade Diameter	113 mm	Starting Voltage	8.4 V
Hub Size	47 mm	Weight	160 g
Data in green cells provided by the manufacturer or observed; data in the blue cells were measured.

 

Stock Fan Measurements
Voltage	Avg. Speed	SPL@1m
12V	610 RPM	11 dBA
10V	490 RPM	<10~11 dBA
Measuring mic positioned 1m at diagonal angle from the center of the heatsink. Ambient noise level: 10~11 dBA.

As for the noise level of the fan, it’s almost nonexistent. When mounted on the heatsink, It produces a slight hum at close proximity but is completely inaudible at one meter’s distance, even at full speed. It barely registered on our sound meter, measuring about half a decibel more than our anechoic chamber’s noise floor. This is about as close to silent as it gets, and undervolting it is pointless unless the fan is going to reside right next to your ear.

With both stock fans installed, the Venomous X measures just 11~12 dBA@1m.

With both fans mounted on the heatsink, there was barely any increase in noise level. Running the pair at full speed is slightly quieter than the 12 dBA@1m generated by our reference Nexus 120 mm fan running at just 7V.

Cooling Results

Fan Voltage	One Fan		Two Fans
	SPL@1m	Thermal Rise	Thermal Rise	SPL@1m
Stock Fan: Thermalright TR-FDB-12-600
12V	11 dBA	47°C	42°C	11~12 dBA
Reference 120mm Fan: Nexus Real Silent
12V	16 dBA	38°C	36°C	18 dBA
9V	13 dBA	41°C	39°C	14 dBA
7V	12 dBA	43°C	40°C	12~13 dBA
Reference 140mm Fan: Noctua NF-P14
12V	28~29 dBA	38°C	36°C	30~31 dBA
9V	21 dBA	40°C	38°C	22~23 dBA
8V	18 dBA	41°C	39°C	19 dBA
7V	15~16 dBA	43°C	41°C	16~17 dBA
6V	13 dBA	44°C	42°C	14 dBA

With a single stock fan, the Venomous X was a mediocre performer with a thermal rise of 47°C, however this was an impressive result as it was inaudible. Adding the second fan improved cooling by 5°C while barely affecting the overall noise level. Doubling up the stock fans gave us slightly better acoustics and temperatures than our reference Nexus 120 mm fan running at 7V. This too was commendable as the Nexus is the best performing fan we’ve come across.

Using two reference fans resulted in only a 2~3°C improvement but also on emitted 1 dB more using the stock fans, so it’s not a conclusive which combination is superior. Our reference Noctua 140 mm fans actually performed slightly worse, allowing the processor to heat up about 2~3°C more than the Nexus fans at comparable noise levels.

Heatsink Comparison Tables

Single Fan CPU Coolers (ref. 120mm fan): °C Rise Comparison
Heatsink	Fan voltage / SPL @1m
	12V	9V	7V
	16 dBA	13 dBA	12 dBA
Thermalright Ultra-120 eXtreme Rev.C	38	40	43
Thermalright Venomous X	38	41	43
Prolimatech Megahalems	38	41	44
Noctua NH-U12P	39	42	44
Scythe Mugen-2	39	42	45
Cogage TRUE Spirit 1366	40	42	45
Prolimatech Armageddon	40	42	46
Zalman CNPS10X Quiet	40	43	46
Scythe Yasya	41	43	47
Thermalright Ultra-120 eXtreme	40	43	48
Cooler Master Hyper 212 Plus	41	44	48
Thermalright Ultra-120	42	45	49
Titan Fenrir	43	46	50
Scythe Ninja 3	44	47	49
Noctua NH-C12P	43	47	51
Zalman CNPS10X Extreme	43	47	53
Swiftech Polaris 120	46	49	54
Zalman CNPS10X Flex	45	50	54
Cooler Master V8	46	50	54
Scythe Grand Kama Cross	45	52	57
Arctic Cooling Freezer Xtreme Rev.2	49	52	58
Scythe Kabuto	51	53	60

Compared to other large single fan CPU coolers, the Venomous X places a very close second to the Ultra-120 eXtreme Rev.C. Given how similar the heatsinks are constructed, this is not a big surprise. Both coolers are exceptional performers.

Dual Fan CPU Coolers (ref. 140mm fans): CPU °C Rise Comparison
Heatsink	Fan Voltage / SPL*
	8V	7V	6V
	18~19 dBA	15~17 dBA	12~14 dBA
Prolimatech Genesis	36	37	39
Noctua NH-C14	37	39	41
Thermalright Silver Arrow	37	39	41
Noctua NH-D14	38	40	42
Thermalright Venomous X	39	41	42
*Note: there are minor differences in measured SPL due to the variety of fan orientations offered by the compared dual fan coolers.

Venomous X also puts up a pretty good fight against the dual 14 cm fan monsters, coming close to matching the Noctua NH-D14 when using a pair of our reference 14 cm fans.

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.

• Nexus
  120mm fan at 1m
  — 5V (11 dBA@1m)
  — 7V (12 dBA@1m)
  — 9V (13 dBA@1m)
  — 12V (16 dBA@1m)

FINAL THOUGHTS

Though obviously unable to live up to its “silent” billing, the Thermalright Venomous X Silent Edition comes as close as an CPU heatsink can to this claim without resorting to passive cooling. As the included fans spin at a meager 600 RPM and employ fluid bearings, they are exceedingly quiet, being effectively inaudible even in our anechoic chamber. They also perform surprisingly well on the Venomous X, giving our reference Nexus 120 mm fans a run for their money. We aren’t big proponents of the plastic fan mounts though — the metal clips work just as well and as a bonus, are compatible with most 14 cm fan models. The heatsink itself, being built from the same mold as the Ultra-120 series, has the same superb cooling proficiency as the Ultra-120 eXtreme Rev.C, thanks in no small part to its convex base and sublime mounting system.

If you’re in the market for a potent CPU cooler that is extremely quiet straight out of the box, the Venomous X Silent Edition fits the bill better than any product we’ve tested in recent memory. Our only complaint is the current street price of US$70~$75. Larger, more capable coolers like the Thermalright Silver Arrow and Noctua NH-C14 can be found for about the same amount, though they both require some fan control magic to match the noise output of the Silent Edition. This isn’t necessarily a bad thing as their higher fan speeds also make them more versatile — an 11 dBA cooler afterall is beyond overkill for many users.

Our thanks to Thermalright for the Venomous X Silent Edition heatsink sample.

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Articles of Related Interest

Prolimatech Genesis CPU Heatsink: Retaking the Crow
Swiftech Polaris 120 CPU Heatsink
Zalman CNPS9900 MAX & CNPS5X CPU Coolers
Thermalright Silver Arrow Dual 14cm Fan Cooler
Noctua NH-C14 Dual Fan Top-down CPU Cooler
Thermalright Ultra-120 eXtreme Rev.C & AC Freezer Xtreme Rev.2

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