We installed the Noctua NF-A14 FLX, NF-A14 ULN and the NF-A15 PWM fan on a Noctua NH-D14 cpu cooler. Our system was powered by an Intel i5 2500K processor (95W) overclocked at 4.5GHz. Using the OCCT testing software we stressed out the system for a full hour and logged the temperature of the CPU and the noise level each of the fans produced.

Compared to the performance of a Noctua's NF-P14 fan (previous model) when installed on a Noctua NH-D14 cpu cooler:

• The NF-A14 FLX fan + NH-D14 cooler system was slightly less efficient, with the temperature of the CPU to be 2 degrees Celsius higher, without using LNA or ULNA.
• The NF-A14 ULN fan + NH-D14 cooler system was less efficient, with the temperature of the CPU to be 4 degrees Celsius higher, without using ULNA.
• The NF-A15 PWM fan + NH-D14 cooler system was impressive, as the temperature of the CPU was decreased by 2 degrees C.

In any of the above cases, enabling the LNA or ULNA would have a further effect on the cooling efficiency of each system. However, it would make a great sense to use these features in order to reduce the noise of the spinning fans.

To sum up, the Noctua NF-A14 series is armed with all the latest technologies from Noctua and comes as a well-balanced fan either for cases or cpu coolers.

Using the included adapters, the FLX version can be adjusted to spin at 1200rpm ~ 900rpm, offering a very quiet operation. Compared with the company's previous 140mm fan - the NF-P14 - the NF-A14 FLX cannot fully match its cooling performance, although it follows closely.

The ULN version is can be adjusted to spin at 800rpm ~ 650rpm, making it one of the most quiet 1400mm fans available today. However, the price is the relatively weak cooling performance at such low RPMs. Compared with a NF-P14, the NF-A14 ULN is not a performance champion, but remember that this fan is aimed for maximum quietness.

If you need the absolute performance, you may go for the Noctua NF-A15 PWM. This one is also armed with all the latest technologies from Noctua successfully replaces the legendary NF-14. The combination of the Noctua NH-D14+NF-A15 PWM will give you at least a 2 degrees Celsius advantage over the NF-P14+Noctua NH-D14 setup. For that performance you will have to pay around $23 ad you'll get a full retail package, great performance and a fan that is not more noisy than the NF-P14.

Noctua NF-A14 FLX	Noctua NF-A14 ULN	Noctua NF-A15 PMW
Pros: Complete retail package Good price Fits into case/cpu coolers Can be very silent with the included adapters 6 years warranty Cons: Somewhat lower performance compared with NF-P14	Pros: Complete retail package Good price Fits into case/cpu coolers Can be extremely silent with the included adapter 6 years warranty Cons: Not a performance fan for hardcore users	Pros: Complete retail package Good price Best performance you get from an 140mm fan Relatively silent product 6 years warranty Cons: