Fan Design

The 92mm, 7 blade fan on the Thermaltake TMG A1 is rated to spin up to 2500 rpm. At this speed it can move over 35.14 cubic feet of air per minute and is rated to it at 16 decibels or 0.7 Sone. Personally, I think this is a tad bit on the generous side but this is what the specs say.

As for construction, Thermaltake opted for a non-standard all black plastic body with a modified frameless design. In a nutshell the fan has a very thin housing bracket on the heatsink facing side that is strong enough to allow it mount the cooler, and survive the torque the fan places on it, but does not impede air flow.

More importantly this “frameless” design coupled with its aggressive scimitar style fan blades help to reduce air turbulence. Below a certain noise level the air itself can become the largest single source of noise created by a fan. At this noise level principles like fluid dynamics actually come into play. What this means is that the air itself can be seen to act like any fluid medium and by reducing the friction or turbulence it encounters you can actually make the air itself quieter.

The fact that Thermaltake engineers took into account these advanced principles is very impressive and its does pay dividends. This is where the ultra low “Sone” rating of 0.7 comes into play. Sone is a unit of measure that describes perceived noise levels. Unlike the Decibel scale, where two identical sounds can be perceived by humans as more or less “noisy”, the Sone scale takes into account what people can hear. This way it not only describes how loud something is but also how noticeable it is.

Here is the TMG A1’s DBA to CFM ratio as claimed by Thermaltake:


Here is the TMG A1’s Sone to CFM ratio as claimed by Thermaltake:


Overall this should be a very, very quiet fan. The only concern with this fan its low CFM rating. A much higher rating would have produced more noise but honestly when you get below the noise level of the other fans in your system it is wasted. We would have liked to have seen it rated at a much higher 50cfm, even if this meant it was a 1.0 Sone versus a 0.7 Sone fan. However, as it can use a standard 92mm fan (albeit with a bit of work), if the fan included does not meet your needs or dies after the warranty ends it should be relatively simple to replace with a faster fan.

The next thing we did was to take apart the fan and see how well it was mounted. In a very nice move, considering the price range, the fan is mounted to the heatsink with anti-vibration springs. The fan is still solidly connected so there is hardly any chance of it falling off; it is just the vibrations do not get transferred to the heatsink. These little springs are surprisingly good at eliminating fan vibration noise and this is a good effective compromise between reducing noise and securely mounting the fan.