Specification and Test Methodology
To put CPU cooler performance into perspective we're benchmarking using a high-end Intel Haswell test platform. A detailed description of the CPU cooler being reviewed, our test platform and all comparison coolers can be found in the tables below.
Fractal Design Kelvin S24 Specification
|Socket compatibility||Intel: 775, 1150, 1155, 1156, 1366, 2011|
|AMD: AM2, AM2+, AM3, AM3+, FM1, FM2, FM2+|
|General Specifications||Block/pump assembly measurements: 69*69*40mm|
|Tubing Measurements: 320mm long, 11mm outer and 8mm inner diameter|
|Fitted with anti-kink coils for worry-free installation|
|Kelvin S24 Radiator Measurements: 30*124*275mm|
|Thread class for fill port and all tube fittings: G 1/4"|
|Fans included: 2|
|Fractal Design Zero™ Thermal Paste ; 1g syringe, sufficient for multiple mountings|
|Colours Available: Black|
|Net weight - Base unit only, not including mounting or fans: 1.2kg|
|Net weight - SS-HP fan, per fan: 165g|
|Package dimensions - W x H x D: 350*250*151mm|
|Package weight: 2.5kg|
|Fan Specification||Fractal Design Silent Series HP 120mm|
|800 - 1700RPM|
|Max air flow: 62.4CFM|
|Max pressure: 2.33mm H2O|
|Acoustical noise: 26.9dB(A)|
|DC 12V, 0.18A|
|Pump Specification||Ceramic bearing|
|Maximum water flow: 72 l/h|
|Maximum pressure: 1.0m H2O|
|Acoustical noise: 25.0dB(A)|
|DC 12V, 0.27A|
|Package Contents||Fractal Design Kelvin S24 pre-assembled Water Cooling Unit|
|2 Fractal Design Silent Series HP PWM controlled fans|
|Intel 775,1150,1155,1156,1366 mounting hardware (including back plate)|
|Intel 2011 mounting hardware|
|AMD AM2,AM2+,AM3,AM3+,FM1,FM2,FM2+ mounting hardware|
|PWM splitter cable|
|Fractal Design Zero™ Thermal Paste, 1g Syringe|
|Long and short radiator mounting screws|
HEXUS CPU Cooler Test Bench
|Hardware Components||HEXUS Review||Product Page|
|Processor||Intel Core i7-4770K (quad-core, overclocked up to 4.40GHz)||June 2013||Intel.com|
|Motherboard||Asus Z97-A||May 2014||Asus.com|
|Memory||16GB Corsair Vengeance Pro (2x8GB) DDR3 @ 1,866MHz||-||Corsair.com|
|Graphics Card||Nvidia GeForce GTX Titan (6GB)||February 2013||GeForce.com|
|Power Supply||Corsair AX760i||-||Corsair.com|
|Storage Device||Crucial M500 240GB SSD||July 2013||Crucial.com|
|Chassis||Corsair Graphite Series 600T||October 2010||Corsair.com|
|Monitor||Philips Brilliance 4K Ultra HD LED (288P6LJEB/00)||-||Philips.co.uk|
|Operating system||Windows 8.1 (64-bit)||October 2012||Microsoft.com|
|Fan(s)||Fan speed||Radiator dimensions||Heatsink dimensions (inc. fans)||Warranty|
|Zalman LQ315||1x Zalman ZP1225ALM 120mm||900 RPM - 2,000 RPM|| Width: 120mm
|Fractal Design Kelvin S24||2x Fractal Design Silent Series HP 120mm||800 RPM - 1,700 RPM|| Width: 275mm
|Intel Reference E97378-001||1x Intel PWM 92mm||1,200 RPM - 2,800 RPM||-||Height: 50mm
|Noctua NH-D15||2x Noctua NF/-A15 140mm||300 RPM - 1,500 RPM||-||Height: 165mm
To get a feel for how the above coolers compare, we run our Core i7-4770K processor overclocked to 4.4GHz. In order to push the coolers, voltage is upped to an above-average 1.2V and memory operates at 1,866MHz using the built-in XMP profile.
Temperature is logged while a large 4K video clip is encoded using the freeware HandBrake utility. The workload tasks all four cores/eight threads, and in order to provide a stabilised reading, we then calculate the average temperature across all four cores from the last few minutes of encoding.
Actual CPU temperature is recorded, but to take into account any fluctuations in our lab, we also graph the delta temperature - that's CPU temperature minus ambient temperature. And, last but not least, to give you an idea of cooler acoustics, we use a PCE-318 noise meter to measure overall system noise in both idle and load states.
Our Corsair Graphite Series 600T chassis is set to run with three installed fans; a 200mm Corsair front intake; a 200mm Corsair top exhaust; and a 140mm Noctua NH-A15 rear exhaust. The front and top fans are configured to run quietly using a custom DC profile from within the Asus BIOS, while the rear exhaust and CPU cooler are set to the 'standard' PWM profile. Where necessary, any of the three aforementioned fans are removed to make way for radiator installations.
Any fans connected to a radiator are configured per the manufacturer's recommendations. If none are made, fans are set to draw air in from outside the chassis (thereby ensuring that the delta between the air temperature and the temperature of the radiator is maximised).
The Fractal Design Kelvin S24 is the second cooler to be tested on our new Intel Core i7-4770K test platform. For comparison, we've included benchmark results from the Intel reference cooler, a high-end Noctua NH-D15 air cooler and a Zalman LQ315 liquid cooler.