Noise levels
Noise levels
With a certified dBA meter we measure how many dBA originates from the PC. It's slightly subjective as there is always noise in the background, from the streets, from the HD, PSU fan etc etc, so this is by a mile or two, not a precise measurement. You could only achieve objective measurement in a sound test chamber. Please take this measurement as an indication, not precise measurement.
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) | 120 dBA | |
Construction Site | 110 dBA | Intolerable |
Shout (5 feet) | 100 dBA | |
Heavy truck (50 feet) | 90 dBA | Very noisy |
Urban street | 80 dBA | |
Automobile interior | 70 dBA | Noisy |
Normal conversation (3 feet) | 60 dBA | |
Office, classroom | 50 dBA | Moderate |
Living room | 40 dBA | |
Bedroom at night | 30 dBA | Quiet |
Broadcast studio | 20 dBA | |
Rustling leaves | 10 dBA | Barely audible |
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. The PC again stressed at 3300 MHz on the CPU with 80% RPM on the ventilator. These as such are noise levels measured under heavy CPU load:
On average and especially PWM controller, the noise level as such will be much lower. The cooler does have another strong selling point, though not silent if the CPU is heating up -- it is not very noisy with it's low RPM rating.
Our setup maxed out at roughly 41~42 DBa. So you can hear the ECO, but it's not irritating or anything. Once your system IDLES fan RPM will get back to roughly 60RPM after which DBa levels fall back under 40 DBA.
But let's really push the cooler and overclock some more, shall we ?