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Fractal Design Celsius S24 AIO CPU Cooler Review

Poorna Shankar Posted:
Hardware Reviews 0

Cooling is an absolutely vital part of a gaming PC. Lower temperatures allow you to push higher clocks for greater performance. There are plenty of great air coolers out there from brands like Noctua, but I've always preferred liquid cooling. I like the look, the low noise, and extra space it frees up over a standard tower cooler. Today, we're taking a look at the Fractal Design Celsius S24, a 240mm radiator with some unique design features. How does it compare against my trusty, similarly-priced 240mm Corsair H100i v2? Let's find out.


General Specifications

  • Price: $120.99 (Amazon)
  • Coldplate technology: Fifth generation
  • Coldplate material: Copper
  • Additional sound dampening: Integrated
  • Thermal paste: Pre-applied, high thermal conductivity
  • Sockets supported (Intel): 1150, 1151, 1155, 1156, 1366, 2011, 2011-v3, 2066 (via included 2011-v3 kit),
  • Sockets supported (AMD): AM2, AM2+, AM3, AM3+, AM4, FM1, FM2, FM2+, TR4 (via included bracket in AMD Threadripper box) 
  • Tube length: 400 mm
  • Tube material: Sleeved low-permability rubber tubes
  • Fittings, block side: Durable metal fittings, non-removable
  • Fittings, radiator side: Durable metal fittings, G 1/4" thread
  • Thermal paste: Pre-applied, high thermal conductivity
  • Fan control: Integrated dual mode
  • Warranty: 5-year (Upon Expansion of the Celsius unit, only individual components of the Fractal Design Celsius S24 or S36 are covered)

Fan Specification

  • Fan type: Fractal Design Dynamic X2 GP-12 PWM
  • Rotational speed: 500-2000 RPM
  • Bearing: LLS bearing
  • PWM control: Yes
  • Acoustical noise (full speed): 32.2 dB(A)
  • Maximum air flow: 148.8 m3/h | 87.6 CFM
  • Maximum static pressure: 2.30 mm H2O
  • Input voltage: 12 V DC
  • Maximum input current: 0.2A
  • MTBF: >100,000

Pump Specification

  • Rotational speed: 1950-3150 RPM
  • Bearing type: Ceramic bearing and shaft
  • PWM control: Yes
  • Acoustical noise (full speed): 20,0 dB(A)
  • Maximum pressure, 50°C: 1m H2O | 1.45 PSI
  • Input voltage: 12 V DC
  • Input current (without fans): 0.15 A
  • Rated input power (with fans): 6.6W
  • MTTF: >50,000 hours

Radiator Specification

  • Dimensions: 284*122*31 mm
  • Housing material: Aluminium
  • Fin material: Aluminium
  • Port threads: G 1/4"
  • Fan screw threads: UNC 6-32


Featuring a sleek black design with woven tubing, the S24's design isn't too dissimilar to other all-in-one (AIO) coolers on the market today. The cooler ships with two 120mm fans, all the brackets necessary for both Intel and AMD mounting, and of course, the radiator itself.

I was most intrigued by Fractal's use of onboard PWM headers for the fans. These headers are mounted directly onto the radiator itself, which is extremely convenient. I find this to be such a unique feature which I personally haven't seen on AIOs before, and was most interested in checking out.

Mounting the fans onto the radiator and then plugging them into the radiator PWMs was extremely convenient. The radiator only has a single woven cable which plugs into your motherboard PWM, which results in an overall clean look. There aren't multiple cables you have to deal with and cable manage. I find this convenient and an intelligent solution for cable management.

Keep in mind, there is no software control for the S24. You control the fan curves with this dial on the pump itself. The pump dial has two settings: Auto and PWM. Auto is the default curve, while PWM is the more aggressive fan curve. I tested with both settings, as the results will indicate. I personally found this extremely convenient, though, you can control the exact fan curves in your bios if you want even more granularity. However, those looking for finer control via desktop software may be disappointed.

Overall, the Fractal Design Celsius S24 is an extremely sleek, well-designed package which will fit the design language of almost any case. I love it.


Testing consisted of both synthetic and gaming performance, with the focus on temperatures and noise. Unfortunately, I do not have a decibel meter with me at this time. However, we can look at the RPM measurements of the S24, coupled with how audible the system is in real-life scenarios when under load.

The test system is as follows (all components provided by the author except the cooler being reviewed):

  • Chassis: Lian Li O11 Dynamic
  • CPU: Intel i7 8700k (OC @ 4.7 GHz)
  • GPU: Zotac RTX 2080 Ti AMP Edition
  • Motherboard: Gigabyte Z370 Aorus Gaming 7
  • RAM: 16 GB G.Skill Trident Z @ 3200 MHz
  • Power Supply: Corsair RM 850i
  • Fans: 3 x 120mm Lian Li Bora Digital
  • AIO: Corsair H100i v2, Fractal Design Celsius S24 (review product)

The Lian Li Bora fans are mounted on the side of the Lian Li O11 Dynamic case, and intake fresh cool air. Both the Corsair and Fractal Design AIOs were mounted at the top of the case with the fans in a push configuration, exhausting air through the top of the chassis.

I tested both productivity apps and games. Between each run, the CPU was allowed to come down to normal operating temperature. Productivity was tested with Aida 64, 7-Zip, and Cinebench. Because the S24 features an Auto and PWM setting for its hardware fan control, both settings were tested. All games were run at 1080p to stress the CPU. Temperatures and RPM were measured using HW Monitor.

Game Considerations:

  • GTA V Benchmark: All Graphics and Advanced Graphics sliders/options max or enabled
  • Metro Exodus Benchmark: DX 12, all sliders/options maxed or enabled, Nvidia GameWorks off, RTX/DLSS off
  • Elder Scrolls Online: Alinor city circuit, general combat, all sliders/options maxed or enabled
  • Witcher 3: Novigrad circuit, all sliders/options maxed or enabled, Nvidia GameWorks off


First up, let's look at productivity.

In general, the S24 in Auto mode performed similarly to the Corsair H100i V2 for average temps. The max temps were a bit higher in 7-Zip and Cinebench, for example, but overall, the S24 turned in similar results.

When set to PWM mode, the results were similar with the exception of Cinebench. Both average temps and max temps on the S24 were lower in PWM mode when compared to the Corsair. I'll get to discernable noise in a moment, but these numbers illustrate the difference between Auto and PWM modes with respect to productivity applications.

Gaming performance was more interesting. The S24 turned in higher average temps in GTA V when set to Auto, while actually performing cooler than the Corsair when set to PWM. The temps in Metro Exodus were so close that these one degree differences can be negligible.

However, when looking at Elder Scrolls Online and The Witcher 3, we see that while Auto mode on the S24 performs similarly to the Corsair, the PWM results are significantly cooler. ESO in particular shows average temps of four degrees cooler than the Corsair.

Throughout productivity and gaming testing, I measured RPM when set to Auto to fall between 1900 - 2000 RPM. With headphones off, it was extremely quiet. In fact, the S24 was quieter than the Corsair.

The RPM when set to PWM mode fell between 2800 - 2900 RPM. While this is much faster and more audible, the S24 was still relatively quiet, even without headphones. More importantly, the pitch of the sound wasn't high frequency, and instead sounded more like a gentle hum. It would be very difficult to hear the S24 through headphones when gaming normally.


I'm very impressed with the Fractal Design Celsius S24. The onboard PWM fan headers, woven cables and tubing, and extremely sleek design really speak to my personal minimalist style. The fans are quiet and efficient at dissipating heat under normal productivity and gaming situations.

When compared against the Corsair H100i v2, it performs similarly in Auto mode, and cooler in PWM mode. But even in PWM mode, the noise was kept to a minimum. The price differential from the $130 Corsair to the $121 Fractal Design S24 is only $10. You can't go wrong with either radiator.

However, after my testing concluded, I left the S24 in my system because of the excellent clean design, and its relatively silent operation. It's a great radiator for this price bracket, one which I have no issue recommending.


  • Onboard PWM fan headers provide clean design
  • Simple pump toggle
  • PWM pump mode actually provides better temps
  • Quiet operation


  • Lack of software doesn't allow for finer fan curve control

Product discussed here was provided by the manufacturer for purposes of this review.


Poorna Shankar

A highly opinionated avid PC gamer, Poorna blindly panics with his friends in various multiplayer games, much to the detriment of his team. Constantly questioning industry practices and a passion for technological progress drive his love for the video game industry. He pulls no punches and tells it like he sees it. He runs a podcast, Gaming The Industry, with fellow writer, Joseph Bradford, discussing industry practices and their effects on consumers.