How To Choose A CPU Cooler

Finding The Best Fit

Gaming tower cases are often among the least restrictive in accommodating cooler size. Recent case designs have grown wider to accommodate tall tower-style CPU coolers, taller to accommodate top-panel radiators, and sometimes deeper to accommodate front-panel radiators. Relocated internal bays and the reduction or exclusion of external bays allows some case designers to maximize radiator space without increasing external dimensions.

Cases are still designed to flow front-to-back and bottom-to-top, but no longer use the power supply’s air inlet to supplement an undersized (80mm or 92mm) rear-panel exhaust fan. A larger 140mm or 120mm exhaust fan works in series with the CPU fan and front panel intake fan to direct heat from front to rear. Airflow can be reversed, but doing so fights against convective flow and disables the dust filters which are usually present only on a case’s front and bottom air inlets.

Certain low-cost cases don’t keep up with current design trends, however. As shown above, the heat pipes of a Big Air CPU cooler extend past the side panel of a traditionally sized mid-tower case. Maximum supported CPU cooler height is usually listed in a specification table on the case’s web page.

Cases aren’t always the limiting factor in CPU cooler selection, however. Zalman’s CNPS12X is designed to be offset ¼” towards the graphics card, so that it clears the top panel of most cases when installed on most motherboards. The design relies on the fact that many gaming motherboards have a vacant space where the top expansion slot is supposed to be. Since ours didn’t have that extra space, we had to mount the cooler backward (blowing rear-to-front) in order to test it on an open bench.

Another example, Thermalright’s 170mm-wide Archon SB-E has no offset and overhangs our graphics card slot in either orientation. Blowing towards the graphics card would have been an option if not for it hitting our memory. The design is once again optimized for motherboards that have no card in the top slot position, and further relies on the case’s top panel having some clearance above the motherboard. Both of those requirements are fairly common in gaming systems, but not ours.  

Anyone who thinks that putting a big cooler on a big motherboard might be a big problem needs only look downscale to see real trouble. Various mini ITX motherboards have unique limitations of installation space between the CPU socket and memory, any expansion card, voltage-regulator coolers, and the left edge of certain cases. Most wide, low-profile coolers are offset in at least one direction to maximize use of available space.

Some coolers are even offset in two directions. Note that the cooler below is designed to move the fan away from both the graphics card (offset left) and away from the front edge of the board (offset rear). Specifying these offsets in our reviews allows you to make an informed decision, or a very close guess, at which cooler is the most-appropriate for your motherboard.

Buyers unable to figure out any of these fitment issues can use a smaller cooler or, if their case has any space to mount any radiator, find a liquid cooling system to match that case.

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  • HEXiT
    i always used air coolers.
    1)way less moving parts.
    2)less maintenance.
    3)less noise.
    4)if something does break its often way less costly to fix.
    5)i find liquid coolers aesthetically ugly unless your spending real money on ptg/glass tubing.

    i do see the advantages of liquid cooling but saying as i build most of the time for other people who dont have a clue about pc's. i just find it way less of a headache to use air.