PC Components

Deepcool Assassin III – Powerful CPU cooler mixes up the high-end segment

Behind the name Deepcool hides a Chinese manufacturer of PC components. Deepcool was founded in 1996 in Beijing, China. To the Produktportfolio of the manufacturer belong among other things cases as well as CPU coolers and compact water cooling systems. About a year ago, Deepcool introduced the Assassin III CPU cooler with the aim of conquering the high-end segment and, above all, taking the crown from Noctua’s NH-D15 air coolers.

On paper, this already looks very promising. With similarly massive dimensions and a weight of almost 1.5 kilograms, the Assassin III is quite impressive. In addition to its cooling capacity, the Assassin III is also expected to impress with its chic design, powerful fans and slightly convex base plate. Finally, the manufacturer advertises the Assassin III with a simple assembly for many bases and a wide range of accessories. If the Deepcool Assassin III can live up to these promises, you will find out in this review.

Technical Details

Cooler specifications

Dimensions (with fan) 140 x 165 x 161mm (W x H x D)
Weight (with fan) 1.46 kg
Material copper (base plate, heat pipes, nickel-plated), aluminum (cooling fins)
Heatpipes 7x Ø 6 mm
Compatibility AMD AM2, AM2+, AM3, AM3+, AM4, FM1, FM2, FM2+ (backplate required)
Compatibility Intel LGA2066, LGA2011-0 & LGA2011-3 (Square ILM), LGA1200, LGA1156, LGA1155, LGA1151, LGA1150
Price € 24.37 *

Fan specifications

Fan designation Deepcool TF140S
Type Fluid Dynamic Bearing
Dimensions 140 x 140 x 25 mm
Speed 400 – 1,400 rpm
Volume max. 34.2 dB(A)
Flow volume max. 153.5 m³/h
Air pressure max. 1.79 mmH²O
Power consumption 2.52 W

Packing & scope of delivery

The fact that the Deepcool Assassin III is a very large CPU cooler can be seen from the packaging. It is very large, made of cardboard and printed in color. By using gray and turquoise colors and a colored product image, the packaging stands out from the crowd. In addition to the technical data and the technical drawings of the heatsink and fan, a list of the most important features has also found its way onto the packaging.

If you open the lid of the box, you are greeted directly by a brown box. This box contains all the mounting accessories (screws, backplate, spacers, brackets, thermal paste), a mounting instruction, a sticker for the case and various connection cables or low-noise adapters. Below the box is one of the two enclosed 140 millimeter fans. This one is also wrapped in cardboard. If you take the fan out of the box, the heat sink can be discovered. To protect all components, the entire CPU cooler was wrapped in two foam elements. Finally, in an inconspicuous, oblong box, there is a practical screwdriver with a very long shaft.

Design & workmanship

In terms of design, Deepcool has not dared to experiment much and has completely abandoned RGB. The heat sink consists of two massive cooling towers with 44 aluminum fins each. The cooling towers are arranged symmetrically above the base, which dissipates heat to the aluminum fins via seven 6-millimeter heatpipes. To create a uniform appearance, all heat pipes, the base plate and the upper aluminum fins were nickel-plated. In addition, two black plastic caps cover the ends of the heat pipes and are connected to the cooling tower via several screws on the underside. The Deepcool logo is not glued on at the factory and is included in the delivery. Here the buyer can decide on the design himself.

The TF140S fans supplied by the company have a frame width of 140 millimeters and are also very simple in design. The frame and fan blades are black and have been given a discreet triangular pattern. Rubberized corners are intended to prevent the transmission of vibrations to the heat sink. However, the design of the nine fan blades is unique to the TF140S. Features include a spoiler at the rear end of the fan blades, which is intended to increase the airflow. Both fans are connected via a black 4-pin PWM cable. A corresponding 4-pin PWM splitter cable is included in the delivery.

Fully assembled, the Deepcool Assassin III weighs almost 1.5 kilograms and takes up a lot of space on the photo table. For comparison, we once placed a conventional CPU cooler next to the Assassin III. With a height of 165 millimeters, however, you should definitely check the compatibility of the case used before buying.


A test system on a benchtable is used for the review. This enables us to exclude factors such as heat accumulation in the case. The test system consists of the following components.

Independent of the socket, Deepcool uses its own backplate to mount the Assassin III. The heatsink is screwed to the front of the mainboard. This seems to be basically stable, but is only made of plastic. With a CPU cooler in this price range we would have definitely wished for a more stable metal backplate.

With our AM4 system, the AMD retention module including the backplate had to be completely removed at the beginning. Afterwards the included backplate was prepared. To do this, the four supplied pins had to be inserted through the backplate and the mainboard was then placed on the prepared plate.

After that, four metal spacers follow on the front side, which have to be screwed onto the pins. Two brackets are now placed on these spacers and screwed firmly to the backplate with four more nuts. Because the AM4 brackets are so wide, there was unfortunately a collision with the upper VRM heatspreader on the MSI B350 PC Mate. By applying some pressure the bracket could still be fixed. Since many other AM4 boards have heatspreaders at this point, you should check the compatibility before buying. Unfortunately there is no such compatibility list at Deepcool.

In the last step, the heat-conducting paste was applied to the CPU’s heatspreader, the heatsink was placed on it and screwed to the front side with the retaining brackets. Here the included screwdriver proves to be very practical.

The built-in cooler covers a large area of the mainboard including the fans and also protrudes over the RAM slots. If you have RAM with high heatspreaders, then you have to either mount the fan higher up or move it to the backside. Features of the heatsink itself are cut out at the appropriate places. If you install the Assassin III on a mainboard with the PCIe-16x-slot on top, it could happen, depending on the socket, that the backplate of the graphics card and the cooler touch each other.

The assembly is basically very simple and was completed quickly. However, if you compare this assembly system with the competition, there is still some room for improvement. The use of a plastic backplate is absolutely inappropriate in our eyes at this price and the weight of the cooler. Furthermore, our mainboard had a collision between the mounting brackets and the VRM heatspreaders. If one would reduce the depth of the mounting brackets a bit, this problem could be solved quickly.

Volume and cooling capacity

As shown in the previous chapter, we use an AM4 system based on the Ryzen 5 1400 and the MSI B350 PC Mate as test hardware. The Ryzen runs on 3.8 GHz at 1.25V. To heat up the processor, it was loaded with Prime95 for 15 minutes. The CPU temperature was then read out using the CPUID hardware monitor.

This stress test was performed in two different scenarios and then compared to the values of the Alpine Föhn Matterhorn Pure and the AMD Wraith Stealth. During the temperature measurements the room had a temperature of about 21° C.

Cooler Operating scenario RPM Temperature
AMD Wraith Stealth 50% PWM 1600 rpm 102 °C (crash)
AMD Wraith Stealth 100% PWM 2650 rpm 87 °C
EKL Alpine Föhn Matterhorn Pure 50% PWM 1050 rpm 65 °C
EKL Alpine Föhn Matterhorn Pure 100% PWM 1500 rpm 61 °C
Deepcool Assassin III 50% PWM 700 rpm 58 °C
Deepcool Assassin III 100% PWM 1300 rpm 55 °C

The Deepcool Assassin III easily manages to leave the Boxed Cooler and Matterhorn Pure behind. At 700 revolutions per minute for both fans, the Assassin III can easily beat the normal CPU cooler with a 120 millimeter fan and achieves a lead of 7°C. At this speed, the fans also operate pleasantly quietly. If the fans are running at full speed, the Ryzen 5 could be kept 3 degrees cooler. But now the fans were clearly audible. Silent fans should definitely keep the maximum speed below 800 rpm.

Conclusion on Deepcool Assassin III

Let us now come to the conclusion of this review. With the Deepcool Assassin III, the manufacturer has succeeded in bringing a very high performance CPU cooler to the market. In addition to the performance, the Assassin III can also convince with a timeless design, a wide range of accessories and easy installation for many different sockets. The overall package is rounded off by two powerful 140-millimeter fans.

However, we must also voice criticism. Among other things, we consider the included plastic backplate to be inappropriate for a CPU cooler weighing almost 1.5 kilograms. In addition, the upper VRM heatspreader collided with our AM4 mainboard during installation and the included fans make quite a lot of noise, but at maximum speed they can clearly be heard from the system.

Last but not least there is the price. At 85 Euro (current: € 24.37 ), the Deepcool Assassin III isn’t exactly a bargain, but is in the same price range as the similarly strong Noctua NH-D15. A big advantage of the Noctua is above all the support and the manufacturer’s promise to always provide new free mounting kits for new sockets (as long as this is possible on the socket). But in return, it comes with the typical brown fans that often don’t match the desired design.

All in all it is, depending on the priority of the buyer, but a close neck-and-neck race between the two opponents. However, the Deepcool Assassin III definitely deserves a recommendation.

Deepcool Assassin III

Value for money


The Deepcool Assassin III is a very performant CPU cooler that doesn't have to hide from the strong competition and is compatible to many sockets.

Simon Lüthje

I am co-founder of this blog and am very interested in everything that has to do with technology, but I also like to play games. I was born in Hamburg, but now I live in Bad Segeberg.

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