The EKWB EK-XLC Predator 240 Liquid Cooler Review
by E. Fylladitakis on December 15, 2015 9:00 AM EST- Posted in
- Cases/Cooling/PSUs
- AIO
- Water Cooling
- Liquid Cooling
- EKWB
Testing methodology
Although the testing of a cooler appears to be a simple task, that could not be much further from the truth. Proper thermal testing cannot be performed with a cooler mounted on a single chip, for multiple reasons. Some of these reasons include the instability of the thermal load and the inability to fully control and or monitor it, as well as the inaccuracy of the chip-integrated sensors. It is also impossible to compare results taken on different chips, let alone entirely different systems, which is a great problem when testing computer coolers, as the hardware changes every several months. Finally, testing a cooler on a typical system prevents the tester from assessing the most vital characteristic of a cooler, its absolute thermal resistance.
The absolute thermal resistance defines the absolute performance of a heatsink by indicating the temperature rise per unit of power, in our case in degrees Celsius per Watt (°C/W). In layman's terms, if the thermal resistance of a heatsink is known, the user can assess the highest possible temperature rise of a chip over ambient by simply multiplying the maximum thermal design power (TDP) rating of the chip with it. Extracting the absolute thermal resistance of a cooler however is no simple task, as the load has to be perfectly even, steady and variable, as the thermal resistance also varies depending on the magnitude of the thermal load. Therefore, even if it would be possible to assess the thermal resistance of a cooler while it is mounted on a working chip, it would not suffice, as a large change of the thermal load can yield much different results.
Appropriate thermal testing requires the creation of a proper testing station and the use of laboratory-grade equipment. Therefore, we created a thermal testing platform with a fully controllable thermal energy source that may be used to test any kind of cooler, regardless of its design and or compatibility. The thermal cartridge inside the core of our testing station can have its power adjusted between 60 W and 340 W, in 2 W increments (and it never throttles). Furthermore, monitoring and logging of the testing process via software minimizes the possibility of human errors during testing. A multifunction data acquisition module (DAQ) is responsible for the automatic or the manual control of the testing equipment, the acquisition of the ambient and the in-core temperatures via PT100 sensors, the logging of the test results and the mathematical extraction of performance figures.
Finally, as noise measurements are a bit tricky, their measurement is being performed only manually. Fans can have significant variations in speed from their rated values, thus their actual speed during the thermal testing is being acquired via a laser tachometer. The fans (and pumps, when applicable) are being powered via an adjustable, fanless desktop DC power supply and noise measurements are being taken 1 meter away from the cooler, in a straight line ahead from its fan engine. At this point we should also note that the Decibel scale is logarithmic, which means that roughly every 3 dB(A) the sound pressure doubles. Therefore, the difference of sound pressure between 30 dB(A) and 60 dB(A) is not "twice as much" but nearly a thousand times greater. The table below should help you cross-reference our test results with real-life situations.
The noise floor of our recording equipment is 30.2-30.4 dB(A), which represents a medium-sized room without any active noise sources. All of our acoustic testing takes place during night hours, minimizing the possibility of external disruptions.
| <35dB(A) | Virtually inaudible |
| 35-38dB(A) | Very quiet (whisper-slight humming) |
| 38-40dB(A) | Quiet (relatively comfortable - humming) |
| 40-44dB(A) | Normal (humming noise, above comfortable for a large % of users) |
| 44-47dB(A)* | Loud* (strong aerodynamic noise) |
| 47-50dB(A) | Very loud (strong whining noise) |
| 50-54dB(A) | Extremely loud (painfully distracting for the vast majority of users) |
| >54dB(A) | Intolerable for home/office use, special applications only. |
*noise levels above this are not suggested for daily use
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shaolin95 - Thursday, December 17, 2015 - link
er no...its the top Air Cooler but no it does not "blow away almost all of these coolers" plus not everyone likes such huge thing on your build.I used to my tastes got refined and no longer like that huge chunk of metal there not to mention that its harder to clean between fins compared to a radiator.
stren - Thursday, December 17, 2015 - link
Yes using a lab grade setup like that is great for more accurate system measurements. It's damn hard to test radiators well after all - ask my buddy fast_fate about that. *But* a good amount of performance can be gained or lost from bow of the CPU block and how well it matches the CPU's IHS. One thing you failed to mention in your methodology is how the block was mounted to the heater plate. Which TIM was used? How many mounts did you do? Mounts can produce quite variable results. Typically a 1C variance might be seen in mounting one block to one CPU in one orientation. Different CPUs and orientations will produce a wider spread still. In addition measuring ambient air in is extremely hard to do well even if your sensors are world class. How many sensors do you use, how spread out are they, how far from the fans are they? Is there an intake manifold? Is the manifold restrictive? Is there any other airflow in the room? How much does the ambient change? What's the error in the system? How long do you log for, how many runs do you average etc etc?If you were to test CPU water blocks independently on a such a setup the results would be very different to those testing on a real motherboard/CPU. This is particularly true when a small difference in mount height can change mounting pressure and hence TIM thickness. Some block mounts bottom out rather than relying on a set torque to tighten and hence making your own mount will mean a difference in mounting pressure than a real motherboard/CPU combo.
In essence while you're testing *part* of the system very accurately, you're not testing the whole system accurately. While I applaud the effort to measure AIO's well, I think you'd do well to drop the lower power runs where the margin of error is > than the difference in the data in order to save time and also test with a CPU to try and see some impact of the mount on a real world system. Of course the latter can be frustrating to get the accuracy required. Taking data on ten water blocks accurately on one CPU can take me a month. So I can understand why you'd want to limit the variables, but it might be wise to mention that by limiting the variables in order to be more accurate you are also making the test less accurate by being a simulation of the real thing.
r4serei - Friday, December 18, 2015 - link
i'm lovin my 240. i've already expanded onto it with a block for my gpu and another rad. was surprisingly simple.r4serei - Wednesday, January 13, 2016 - link
EK has issued a recall for all revision 1.0 Predators due to a faulty O-ring. It's been corrected on revision 1.1 which has been released as of Jan 4th.alexrw - Saturday, January 30, 2016 - link
> the pressure triples for every increase of 3 dB(A)err, doubles ... actually almost doubles (the exact value when it exactly doubles is not 3dB but 10*log10(2)=3.0102999 dB, or conversely the ratio for exactly 3dB is not 2 but 10^(3/10)=1.99526)
file2man - Sunday, October 30, 2016 - link
I recently purchased the ekwb extreme 360 kit- it has a separate pump, reservoir, clear tubing for somwhere around $350 at microcenter. the pump is not variable speed like most other bought outside of kits and can only vary its speed by a fan controller. Im new at liquid cooling but I suspect hard tubing will in the longer term attract less sediment and is much preferred . Have not reached ek yet but not sure if I can use the 360 extreme kit fittings 13/10mm g1/4 for hard tubing literature says soft tubing is 9.5mm/12.7mm (3/8/1/2 inch). Any help is appreciated since is no way to email ek