Page 7 - Noise Levels with Crossfire
Noise Levels coming from the graphics card
When graphics cards produce a lot of heat, that heat usually needs to be transported away from the hot core as fast as possible. Often you'll see massive active fan solutions that can indeed get rid of the heat, yet all the fans these days make the PC a noisy son of a gun. I'm doing a little try-out today with noise monitoring, so basically the test we do is extremely subjective. We bought a certified dBA meter and will start measuring how many dBA originate from the PC. Why is this subjective, you ask? Well, 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.
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 |
We start up a benchmark and leave it running for a while. The fan rotational speed remains constant. We take the dBA meter, move away 75 CM and then aim the device at the active fan on the graphics card.
| Download (click) - low resolution WMV (6MB) |
| Download (click) - high resolution WMV (25MB) |
There's no other way of saying this ... The card is very noisy. With the fan in idle it's really okay. But every now and then the RPM of the fan will quickly spin faster, and that makes a lot of noise.
Even in desktop mode this happens. With Vista; Aero will definitely stress the graphics card some more, so I predict you could get irritated by this. AMD has acknowledged this and stated that they will fix it soon.
In Idle you can expect a dBa level of roughly 48. This already is moderate. But as mentioned, the card's fan will spin up even when you are doing nothing, and then we hit a 53 dBa volume level coming from the PC. This is very audible.
But if you think it's loud .. try Crossfire. We got close to 60 DBa; and in fact found it so daunting that we made a small video about it, check it out.
When you watch a movie clip be sure turn up your volume, try to focus on my voice and then observe how loud the fans are.
