Please refer to the dedicated test setup page as it applies to this review as well and I did not want to go over it separately to save on review space.
Montech rates the RPM range of the AX120 PWM RGB fans from 800 to 1600 RPM. Of course there will be variations between samples, and airflow resistances will play a big role, too. The provided two samples went from an average 1657 RPM at 100% PWM down to 758 RPM at 31%, following which the fans remained at the same speed all the way down to 1% PWM duty cycle. These numbers fall within rated specs so there is no problem on that front, although the actual range of control remains relatively meager and on a narrower duty cycle range too. We also now know for sure that these fans do not have a zero-RPM mode which would have been nice to see. The overall RPM range should be enough for PC cooling use—at least as case fans—and the RPM response curve is relatively linear. Note also the barely visible error margins indicating minimal sample variation too. Context is needed to talk more about the fan's relative performance and noise, so I have comparison charts below for some fans tested at set RPM values, or as near as they can get to those.
The charts above help put the Montech AX120 PWM RGB fans in better context with the chosen RPM values reflecting usage scenarios most popular with watercooling, although some fans go higher as is the case here. The charts are to be considered for comparison within this result set only and are not to be compared with results from another test elsewhere, owing to different testing conditions. Note that these are average values for all samples of each fan and do not reflect any sample variation, and I will also place another caveat here given these are presumably intended by Montech to be more airflow optimized for use as case fans rather than radiator fans. As such, the relatively low airflow through the radiator is not a surprise. In fact, you need to ramp up the fan speed closer to the max levels to get a substantial increase in airflow relative to lower fan speeds, which in turn also increases the associated noise from the generated air flow. These fans are not high performers thus, and are more on the quieter side mostly as a result of just not pushing much air through. But even here we see there are quieter fans relative to the airflow pushed through the radiator, and it is plausible that the best operating scenario for this fan is when it is up against less airflow restriction such as a case filter.
Instead of having CFM/dBA charts that can potentially be taken for more than they really offer, I am going to show three other fans as a comparison for further context. These include the subject of this review—the Montech AF120 PWM—in addition to three other RGB fans currently sold on the market in the form of the EK-Quantum Impulse 120 D-RGB, CORSAIR AF120 RGB ELITE, and the Thermaltake SWAFAN 12 RGB. There is also the Lian Li UNI FAN SL INFINITY 120 for those wanting a different RGB lighting effect and cleaner cable management as well as the be quiet! Light Wings for those who want a better balance of fan RPM range, RGB lighting and performance. Overall we can see the Montech AX120 PWM is one of the less impressive fans from a performance/noise basis even when directly compared against other RGB fans, and these include fans that have many more LEDs and shorter fan blades too.