Top Tier CPU Air Coolers Q3 2015: 9-Way Roundup Review
by E. Fylladitakis on July 6, 2015 8:00 AM ESTTesting 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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Narcissist - Tuesday, July 14, 2015 - link
I fully agree with the Oxford Guy. I've got a NoFan CR-95C cooling my non-OC i7 4790K. This in conjuction with a couple of M.2 SSD-units, a passively cooled PSU and a passively cooled graphics card makes for a 100% quiet and rather powerful computer. To be on the safe side I've added a Noctua D14 which is configured to force air across all components when the motherboard temperature gets over 50 degC. I is almost never active, though. I've run the Prime95 "Torture Test" for prolonged periods but the CPU-temp consistently stays below 70 degC. In my opinion the NoFan unit is doing a splendid job, although at a price.Sivar - Friday, February 5, 2016 - link
Listen to Oxford Guy. I've used three NoFan models and they all work amazingly well...as long as your CPU's power consumption stays under 100W. If you use a 6- or 8- core i7, or if you overclock enough to hit the 100W envelope, fanless is not for you.Note that NoFan coolers benefit only slightly when a fan is used. They are truly built as fanless coolers from the ground up.
lagittaja - Monday, July 20, 2015 - link
My HTPC has a G2120 with NH-U12P, HD5670 with Accelero S1r2, 64GB Samsung 830 + 1TB WD Black along with 80+ Plat 400W fanless PSU. Inside Lian Li A05N.Only fans being filtered intake Gentle Typhoon @~600rpm and exhaust Slip Stream ~400rpm.
Pretty overkill cooling wise. Could drop the fan speeds even further..
To answer your question, yes it can easily handle it provided there's a teeny weeny bit of airflow in the case.
Work rig has a HR-02 Macho with 800rpm Slip Stream cooling a 3770K@4.7Ghz/1.336V. Could run it fanless if I'd drop the clocks to say 4.3/1.1 or so..
Cvengr - Friday, December 25, 2015 - link
It would simply be the ratio of surface area of the fins to the surface area of the top of the CPU making contact with the heat collector. The fans merely dissipate the heat more quickly over the same area.The advantage of the fans are to transfer the heat by convection to the outer environment more quickly than allowing the heat to build up closer to other components in the system.
If designed for heat transfer, the other components are likely to have been designed assuming an ambient temperature at a particular max level, say 100-130degF. As the delta Temp between the environment and the part generating the heat will increase, so will the heat flow by conduction.
Intent is to draw the heat as far away from the components as possible.
One problem in these designs is to get the heat away from the CPU, as well as the Motherboard components, as well as other components in the case, so the interior case temperatures don't approach the environmental max design temps of those components.
A disadvantage in building by components, is that the component manufacturers are likely to only design for their particular component or one they support.
A common problem in Data Centers is how to remove all the heat from the racks and equipment within them. ANSI/TIA 942 stds go a long way to coordinate between disciplines and trades to effect proper HVAC in the server areas, but even within the racks and cabinets, too many designs limit themselves to providing a temperature set point at different areas in the room, but fail to flow adequate air over the equipment to transfer the heat away from the local electronics environments.
Computer Room Air Conditioners (CRAC) units are notorious for being installed to remove heat, but fail to provide adequate ventilation (air movement) within the computer rooms.
Since most of the CRAC units use split systems (condensate lines in 1/2" copper tubing running through the wall to a condenser outside the building), The natural trend would be to incorporate a small heat exchanger using a CPU water cooling fluid as the secondary, and the chilled water from the condensate of a HVAC system as the primary chilled water to remove the heat.
I haven't shopped the Enterprise level systems. I wonder if such systems are commodities.
sjakti - Monday, July 6, 2015 - link
Interesting article, thank you! I especially appreciate the "Quick Conclusions", that's a great table.Shadow7037932 - Monday, July 6, 2015 - link
I wish you guys had included the Hyper 212+/EVO in the review as the base comparison.zodiacfml - Monday, July 6, 2015 - link
True. It should be the default heatsink to compare with. Now that majority of Intel's CPUs become low power and efficient, these dual tower designs seem overkill except for the unlocked multiplier overclocker or fanless PCs.Achaios - Monday, July 6, 2015 - link
Obsession with CM Hyper 212 EVO "Hypertwohundredtwelvetitis" is a disease also prevalent in Overclock.net. People go berserk over the 212, almost as if they have been mass brainwashed or mass hypnotized. To my best understanding, this mass hysteria is due to the fact that cheap "enthusiasts" may save up to the hugely important sum of $9.99 if they go with the 212 compared to other coolers for the wondrous performance gain of 0.8 Celsius. In other words, the mass hysteria with the 212 is because if you go with the 212, you will save enough money in the end to buy a pack of cigarettes and a can of beer.Nagorak - Monday, July 6, 2015 - link
Well every little bit counts, and to be honest I can understand why people would not want to spend $70-$80 on a heatsink. Getting a decent heatsink for $30-$40 makes sense for a lot of people. However, if you consider wasting money buying cigarettes to be reasonable, I can understand why you wouldn't put much stock in saving a few bucks.Achaios - Monday, July 6, 2015 - link
Given how many overclockers and enthusiasts actually use the CM Hyper Evo 212 in their rigs (as eveidenced at Overclock.net) I think that Zodiacfml's suggestion of the CM hyper Evo 212 being used as a baseline cooler is a good one and I recommend the OP to take it.