Page 2 - A Closer Look - Hardware
As with most fan products these days, the GF120 is made out of plastic with what Deepcool calls TPE cover, which is essentially a soft type of rubber wrapped around the frame for vibration dampening. On top of that, Deepcool provided four rubber grommets for additional vibration dampening when mounted on the case or other hardware of your choosing. The overall design of the GF120 is quite slick in my opinion. It is fully painted black integrated with angles on the frame to make it more visually appealing, especially for those who have a windowed chassis. As for the fan grille, there isn't much to cover the openings to allow maximum airflow. This is opposed to the SilverStone Air Penetrator AP182 that features a fan grille with little spacing, as reviewed by Yours Truly last year. If for whatever reason you decide to work with your fan while your computer is still on, pleased be advised that if you stick your "you-know-what" in there, it would be best to stay away from the spinning blades. Of course, your "you-know-what" being your fingers, obviously.
In terms of blade geometry, it seems to me more and more fan manufacturers are adopting the idea of a bigger width and increased overlap at the end of the blades. This provides more air pressure into the system, and helps focus the airflow for better static air pressure. Most products on the market these days also come with partially or fully sleeved cables, and the GF120 is of no exception. This gives the fan a slick look, and it feels better overall. Upon closer inspection, there is nothing special implemented on the fan blades other than the fact that they are wider. I believe Deepcool could have implemented additional features to reduce turbulance and noise instead of simply relying on vibration dampening rubber and speed reduction from the motherboard. The cable itself was decently long, but when used in a large enthusiast chassis, some users may find it short for what they use it for. It would have been nice if Deepcool could extend the cable itself a bit longer, or have provided an extension cable for those enthusiast users with larger chassis.
The GF120 is equiped with a 4-pin PWM header in which the speed can be controlled by your motherboard, or be powered directly from your power supply via the 4-pin to Molex connector. According to Deepcool's specifications, the fan speed can range from as low as 500rpm to as high as 1800rpm. As aforementioned, the speed could be controlled by your motherboard, and according to their specifications, Japanese Fluid Dynamic Bearings are used to optimize the motor's spin while keeping noise levels down.
Moving on to the topic of sound and CFM, I will now borrow three paragraphs for this article, which were written by my colleague Jonathan in his Noctua NF-F12 PWM and NF-P12 PWM review. This relates to the big challenge when designing fans is to provide the best airflow to noise ratio. One would want the best amount of airflow, while keeping it as quiet as possible. Even with the best ratio, it is quite difficult to measure objectively at all times. The most common unit of objective measurement is CFM (Cubic feet per minute) of air for airflow, and dB noise, respectively. We will go over how application and CFM is related with regards to its standard measurements, but let's discuss perceived noise first.
dB (Decibels) is a logarithmic unit of sound intensity. While it provides what appears to be an objective measurement for the most part, it should be noted that perceived noise levels to the human ear, and actual sound intensity, could result in very different things. Human ears are more sensitive to particular frequencies, and when those particular frequencies are emitted from its source, it may appear louder than its numbers suggest. That same can be said vice-versa -- frequencies that human ears are less sensitive to can actually have louder dB measurements from a sound meter, yet the human ears does not perceive it to be as loud as the numbers suggest. Other factors such as turbulence noise are often not measured correctly, therefore, while it usually provides a good reference, it does not necessarily reflect real life performance.
With regards to the application and CFM, it is generally optimal to have a fan to have a high air volume flow rate -- but as aforementioned, pure CFM values are limited to an extent with regards to its indication on fan performance. It is not completely about how much air in can move per minute quantitatively, but equally as important is how it is executed in reality. Airflow to noise ratio is an essential factor as mentioned earlier. Static pressure is also very important depending on application. High resistance applications such as dense fins on a large heatsink require high static pressure, while case fans needs less static pressure and faster airflow. Its differences in application is like a large truck that has a diesel engine with lots of low end torque for towing, compared to a sports car with a high revving gasoline engine with lots of power to beat around the track -- they are simply designed for different purposes, so choose one appropriate to your needs.
1. Introduction, Packaging, Specifications
2. A Closer Look - Hardware
3. Performance Tests