Fractal Design Celsius S24 Benchmarks & Rating
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Installation, Evaluation & Conclusion
We retain the hardware configuration from previous big cooler reviews while comparing the Celsius S24 to previously reviewed rivals. To retain the stock fan configuration of its Corsair 760T case, we remove the magnetic top vent cover and put our radiators there. Because the case has more intake than exhaust fans, optimal airflow is usually achieved with radiator fans blowing upward and out of the top panel. This also happens to be the orientation shown in the Celsius S24 installation guide.
LGA 115x (1156, 1155, 1150, 1151) interfaces require builders to thread standoff-style mounting posts through the board and into the included support plate. LGA 2011x users (2011, 2011-v3) get a different set of standoffs that use the board’s integrated socket support. AMD users get here by removing the original clip bracket from their motherboards and screwing on either the old-fashioned or new-style posts that are shown on the previous page of this review.
The head unit is then mounted over the posts and secured with cap nuts. A ring that encircles the pump body may be turned to select between internal (temperature based) or external (motherboard PWM-based) speed controls, affecting both the pump and fan motors simultaneously. We chose PWM because our motherboard is capable of reading temperature signals directly from the CPU’s internal thermal diode.
Though the included hoses are 15.25” long, straight fittings on the head unit require builders to also consider the amount of tubing required for any bend. These would have been barely long enough to reach the front pane of our case had we decided to ditch the original fan configuration that has been used for the past two years of CPU cooler reviews.
EK-XLC Predator 240
Swiftech h340 X2
We’re using the aforementioned big cooling test rig and identical test methods to compare Fractal Design’s Celsius S24 to the only three other pre-filled open loops we’ve tested: the XLC Predator 240 from EK, plus Swiftech’s h320-X and h340 X2. Note that Swiftech uses its own naming scheme where “220” means two 120mm; and note that the h340 X2’s two-by-140mm radiator is larger than those of the other samples.
Fractal Design’s Celsius S24 runs cooler than other factory-filled open loops. In fact, it produced the lowest full-load CPU temperature ever measured on this test system. Surely that means it uses higher fans speeds and noisier hardware, right?
Fractal Design’s fans are a little faster than Swiftech’s, but not EK’s. And the Predator 240 doesn’t even have a tachometer output for its pump, as found on the Fractal Design and Swiftech prebuilt kits.
Remember how Fractal Design rated one fan at 32.2 decibels and we said that the second fan would increase noise to 35.2 decibels? Those don’t appear to be unrealistic numbers, as pump noise also contributes to its 35.9 decibel full-speed reading. Only the h320-X was able to beat it in quietness, and then only when comparing the high (max speed) readings of each unit.
Because inferior coolers have often used outrageous fans to produce competitive temperatures, Acoustic Efficiency (aka “cooling-to-noise ratio») is the true measure of performance. The Celsius S24 combines cool temperatures and low noise for a knock-out in this overall performance metric.
While an overall performance win is a great start, it wouldn’t mean much if nobody could afford the winning part. Fortunately, the Celsius S24 is significantly cheaper than its more traditional rivals.
With better cooling performance, better acoustic performance, and less noise than competitors, where could buyers of the Celsius S24 go wrong? What’s missing that could make it so inexpensive? Well, to begin with, the Celsius S24 has no fill port, and that means you’ll probably have to take it out of your system and lay it flat to fill it. Of course, you could add an in-line fill port, and at this price that doesn’t even sound like a big sacrifice.
Yet the Celsius S24 isn’t perfect, as its integrated pump is rated at less than one liter per minute. Fractal Design literature quotes 40LPH, which translates to a mere 2/3 of a liter per minute. The EK pump has four times the flow rating, and the Swiftech pumps are rated four times higher still.
[Editor’s note: We asked Fractal Design whether it sees any issues with adding a standard GPU block to the Celsius loop. Josh Smith, VP of marketing at Fractal Design, said that the company doesn’t see any challenges, and that Celsius was tested in more complex loops during its development. In addressing the issue of flow rate, especially where competitors with open loop coolers are concerned, Josh drew our attention to the particular configuration of the Celsius product, saying: «If by Open Loop coolers you are referring to just that, separate components purchased to create custom loop, then it is possible that they have a higher flow rate. Part of this is due to the fact that many of those pumps are single factor, in the sense that they are a standalone pump compared to Celsius which incorporates a pump and block into the same unit while maintaining size and weight compliance with socket mounting standards. Additionally, many standalone pumps can retail for nearly as much, if not more than the cost of an entire Celsius unit.»]
Without having tested the Celsius unit beyond its CPU cooling functionality ourselves, we’re hesitant to recommend adding anything more than a chipset cooler to the loop at this flow rate. We’re not specifically recommending against it, either, especially given that the company has tested more complex loops. The integrated CPU block appears well-optimized for this flow rate, and we’re up for suggestions on any GPU coolers that may be similarly low-flow optimized.
To avoid spoilers, I waited until I was ready to write the previous paragraphs before even looking at published flow rates. While some might say you might as well get a closed-loop cooler for a little less money, I couldn’t find any closed-loop cooler to match the Celsius S24 performance. Even the four-fan Liquid Freezer 240 trails it by 11%, and it certainly beats all of the factory-filled open-loops presented in today’s review.
The Celsius S24’s performance is nothing less than award winning, but giving it a general recommendation would imply that it’s a top solution for its intended expandable-kit market, and as we noted, we’re not ready to do that without further testing. But we’d certainly recommend using it as delivered or at most adding a chipset cooler. For now, we’re left limiting our stamp of approval to its as-delivered configuration.
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Installation, Evaluation & Conclusion
Prev Page Features & Specifications
Thomas Soderstrom is a Senior Staff Editor at Tom’s Hardware US. He tests and reviews cases, cooling, memory and motherboards.
Fractal Design Celsius S24 Review (Page 3 of 4)
Page 3 — Test Results
Our test configuration is as follows:
CPU: Intel Core i5-6600K @ 3.9GHz (Stock settings)
Motherboard: ASUS Z170-E
RAM: Kingston HyperX Fury HX421C14FBK2/16 2x8GB
Graphics: ASUS GeForce GTX 1060
Chassis: SilverStone Kublai KL07
Power: Corsair RM650X 650W
Storage: Kingston SSDNow UV400 480GB; Seagate BarraCuda ST1000DM003 1TB
Operating System: Microsoft Windows 10 Home x64
— Fractal Design Celsius S24
— Cooler Master Hyper 212 Evo
— CRYORIG A40 Ultimate
— CRYORIG A80
— Scythe Fuma
— Scythe Mugen
All tests were run in our custom-built computer to best reflect real life performance. The computer remained in the same place and room throughout all tests. The ambient temperature in the room was around 22 degrees Celsius. The thermal paste applied to each cooler was stock respective to their manufacturer’s to rate its performance; all pastes had sufficient time for them to settle. The fans on all heatsinks were connected to the same motherboard 4-pin connector. The test computer was turned on and idling for at least one hour for the idling tests. High CPU load results were obtained using the Prime95 in place large FFTs test with four worker threads for a minimum of fifteen minutes, and recorded when the temperature was deemed stable.
There are a few other water coolers and air coolers on this list to have a proper comparison, while as many variables as possible were kept constant. The only 280 mm cooler on the list is the CRYORIG A80, while there are quite large air coolers on the list as well, with one that is a bit smaller. They should give good references for comparison. The Fractal Design Celsius S24 was mounted to the front of the case with both fans attached in a push configuration. The temperature results for each cooler was measured with CoreTemp, which reports the CPU’s integrated digital thermal sensor for maximum accuracy. Each temperature result was calculated by taking the maximum value of the cores inside the CPU.
After idling the computer for more than an hour, the temperature stabilized at 20 degrees Celsius, which was slightly higher than some of the others on the list. However, it was still a nice low number. The 120 mm fans’ RPM were also fairly slow at this point, so it was nice and quiet. I always find the idle tests to be a very small indication of a cooler’s overall performance, so let us not waste more time, and have a look at the load results.
The Fractal Design Celsius S24 stabilized at a temperature of 71 degrees Celsius; a few degrees warmer than the other water coolers, which is expected. The CRYORIG A40 Ultimate has a thicker radiator than the Celsius S24, while the CRYORIG A80 is longer and has larger fans. Both the CRYORIG coolers have more surface area to work with, which at least in part explains the temperature difference. Comparing the results to the others on the list, the Fractal Design Celsius S24 performed admirably. It did do worse than the referenced closed loop units, but the results were by no means bad. Another important feature for a competitive cooler is how quiet it can perform under stress, which the Fractal Design Celsius S24 did well with.
For anyone not using over-the-ear headphones to block out everything except your game or music, silence is pretty important to the enjoyment of using your computer. Using a scale between 0 and 10, where 0 is silent and 10 is a jet taking off, I would rate the Fractal Design Celsius S24 at 2.0/10 at idle, while under load, the sound comes in at 3.5/10. The RPM of the fans really ramp up to keep the system cool, but they were mostly silent during idle. Noise from the pump was mostly inaudible due to some integrated sound dampening. Depending on your sensitivity to noise, the Fractal Design Celsius S24 will be adding very little extra noise while keeping your PC operating in safe temperatures. Perhaps if you are very picky with noise emissions, you could change the RPM range of the pump or the fans, but that will affect cooling performance. The Fractal Design Celsius S24 also has you covered in changing the fan and pump speeds. On top of the pump to the right is a notch indicating if the fan mode is in either Auto or PWM. Twisting the plastic band surrounding the water block allows one to switch between the two modes. According to Fractal Design, in Auto mode, the system will intelligently optimize the pump and fan speeds for a balance between performance and silence. On the other hand, PWM allows the system to be controlled by your motherboard from software.
1. Introduction, Packaging, Specifications
2. Physical Look — Hardware; Installation
3. Test Results
Test and Review: Fractal Design Celsius S24 and Celsius S36 — Two Closed Loop CBOs
Our test lab received two Celsius S24 and Celsius S36 closed loop CBOs from Fractal Design. They promise high cooling performance and low noise levels, as well as the possibility of self-expanding the circuit. It will be interesting to evaluate the new CBOs in practice.
Fractal Design already has some experience with expandable CBOs in the Kelvin range. And the new line Celsius takes it into account. Fractal Design once again allows users to upgrade the CBO by adding, for example, a video card water block to the circuit. The reason lies in the fact that the CBO uses standard G1 / 4 mounts. In addition to the possibility of expansion, Fractal Design focused on reducing noise levels. On the one hand, the manufacturer added vibration isolation to the pump. On the other hand, the speed of the pump and fans can be flexibly adjusted. That is high speeds are set only when they are needed. You can control the speed manually via PWM, but automatic mode is also possible.0005
In contrast to the Kelvin range, Fractal Design decided not to use the single 120mm heat exchanger option. Also, models with 140mm fans have not yet been announced. Fractal Design has so far introduced two models Celsius S24 and Celsius S36 with 240mm or 360mm heat exchangers. The difference in price is small: Celsius S24 will cost 124.99 euros, for Celsius S36 you will have to pay 10 euros more. In Russia, both SVOs have not yet appeared. In any case, both models belong to the upper price segment. But still, Fractal Design’s five-year warranty should be taken into account. For a CBO with a closed loop, this is unusually high.
Before we get into the two Fractal Design CBOs from the Celsius line, let me give you an overview of the specs.
|Model||Celsius S24||Celsius S36|
|Retail price|| EUR 124.