With a certified dBA meter we measure how many dBAs originate from the PC. It's slightly subjective as there is always noise in the background, from the streets, from the HD, PSU fan, etc so this is by a mile or two not a precise measurement. You could only achieve objective measurement in a sound test chamber. Take this measurement as an indication, not a precise measurement please.
The human hearing system has different sensitivities at different frequencies. This means that the perception of noise is not at all equal at every frequency. Noise with significant measured levels (in dB) at high or low frequencies will not be as annoying as it would be when its energy is concentrated in the middle frequencies. In other words, the measured noise levels in dB will not reflect the actual human perception of the loudness of the noise. That's why we measure the dBA level. A specific circuit is added to the sound level meter to correct its reading in regard to this concept. This reading is the noise level in dBA. The letter A is added to indicate the correction that was made in the measurement. Frequencies below 1kHz and above 6kHz are attenuated, whereas frequencies between 1kHz and 6kHz are amplified by the A weighting.
TYPICAL SOUND LEVELS
Jet takeoff (200 feet)
Shout (5 feet)
Heavy truck (50 feet)
Normal conversation (3 feet)
Bedroom at night
But let's have a peek at noise levels. We take a dBA gun and point it at the working PC and take a distance of 75 CM.
So explaining sound is always difficult, but up-to 40 dBA with our testing methodology is considered to be silent .
We now put the processor under 100% load again with the processor under full load for a full Prime95 run. Noise pressure is a difficult thing to explain alright. So if you want silence then up-to 40 dBA is your baseline threshold.
Both coolers, even with two fans installed remains very silent. Remember, these are PWM controlled at Normal settings at motherboard level.
Noctua NH-U12S and NH-U14S review We test and review the Noctua NH-U12S and NH-U14S CPU coolers. Both coolers have recently been introduced into the channel with kicks performance and versus some really nice airflow OWM controlled fans that are drop-dead silent. Hey, it's Noctua .. so you know it's good, let's check out the review shall we ?
Noctua NH-C14 CPU cooler review In the long line of Noctua CPU coolers they introduced another CPU cooler, tagged with the name NH-C14, the heatpipes bent in a C shape and armed with not one, but two Noctua NF-P14 FLX 140mm fans this product is bound to keep any CPU released to date nicely cooled and chilled.
Noctua NH-D14 review It is called the Noctua NH-D14 premium cooler -- but as I like to call it ... the Big Ben. Noctua had to go back to the drawing board and came up with the NH-D14 premium CPU cooler. It is a six heatpipe dual radiator design to improve both cooling performance and noise levels. Obviously what catches the eyes is that dual radiator uneven design with a 140mm fan sitting smack down in the middle of the cooler.
Noctua NH-U9 and NH-U12 heatpipe coolers A new trend that started over the past two years is heatpipe based cooling. Several advantages directly come to mind as the principle is quite simple. You move heat towards another spot other than the source. That way you can get rid of that heat not directly away from that source, yet effectively can cool it down optimally on location B. This means less resources and effort is needed at the original point of heat. The less resources I'm talking about is a direct active form of heat dissipation e.g. loud fans. More cooling these days equals more noise, and don't we all hate it ?