The NH-L12 is the tallest and, at $65, most expensive cooler in our comparison of low-profile heat sinks. Then again, Noctua does include two fans: a 12cm NF-F12 and the 9.2cm NF-B9.
Of course, this gives you the flexibility to maximize cooling when thermal performance is your top concern. Alternatively, if your focus is a low profile, leave the 12cm fan off and take the NH-L12's height from 3.7"-tall to 2.6”. If that's the route you choose to go, it's easy to re-purpose the large blower as a case fan, and the four enclosed rubber grommets can be used to decouple it from the chassis.
Let us briefly mention the bundled accessories: you get a screwdriver, a large syringe of thermal compound, a Y adapter for attaching both fans to a single motherboard header, an extension cable and two voltage-reducing adapter cables that drop fan speed to 1250RPM. While the price of this cooler is significant, it does come with every accessory you may ever need.
Owing to its thick cooling fins, the NH-L12 looks massive and robust. At 23.6 oz. (with both fans) it is the heaviest sink in our test.
Four nickel-plated heat pipes emerge from one side of the base plate. They are trimmed to equal lengths.
Typical of Noctua's other offerings, the CPU-facing side of the base plate is nickel-plated and sanded.
Both fans are mechanically decoupled from the heat sink, the 12cm cooler on top of the radiator by means of its rubber corner inlays and the 9.2cm fan below the radiator by means of two narrow rubber strips glued to the sink.
The fans sport a wide RPM range, enabling quiet operation at idle and massive air flow under demanding loads. When the PWM signal drops below 13-percent duty cycle, the 12cm fan turns itself off. Thus, its RPM range is effectively 0 to 1446RPM. The 9.2cm model spins between 595 to 1783RPM.
Installation And Compatibility
Noctua's instructions are nicely illustrated and quite detailed. For installation on Intel motherboards, a rubber-coated metal back plate is used. This not only insulates the back plate electrically, but also holds the screws in place during installation.
Once the screws are pushed through, four plastic standoffs are added, upon which the socket-specific mounting brackets rest.
Here's where the bundled screwdriver comes into play; use it to tighten the four screws.
Mounting the cooler on AMD motherboards similar, though you use the existing back plate instead.
Don't install the NH-L12 with its bent heat pipes pointing towards the DIMM slots. In that configuration, the sink extends beyond the rear edge of the motherboard and you won't be able to get it into a case. That leaves three usable orientations. Maximum DIMM height is similar in all three cases, ranging from 1.73” to 1.77”.
On mini-ITX mainboards that closely match Intel’s reference layout, the PCIe slot is blocked. Luckily, Noctua publishes a regularly-updated compatibility list.
Noctua's NH-L12is the most expensive product in our story. But it includes two quiet, high-end fans. Strictly speaking, with both of them attached, you might find the NH-L12 to be too tall for your small form factor system. However, since the top 12 cm fan can be removed (leaving the bottom 9.2 cm fan to blow air through the fins), this heat sink can still be used in small cases. You can even reuse the 12 cm fan to exhaust warm air out of your chassis.
With respect to thermal performance, Noctua winds up in the top third, regardless of whether one or two fans are mounted on it. The NH-L12 impresses us not just with its complete accessory bundle, but also as a capable and quiet cooler for discerning enthusiasts.