X-bit labs

Roundup: Four Spire Coolers vs. Four Overclocked Kentsfield Cores in Summer Heat (page 11)

Category: Coolers

by Sergey Lepilov

[ 06/29/2007 | 10:04 PM ]

Noise Level

With this review we introduce noise level measurements into our cooler reviews. The measurement method still needs improvements so your feedback (in our forum) will be welcome.

So, the level of noise from the coolers is measured with a digital noise-level meter Center-321 (0.1dB accuracy) using A-curve weighing.

The ambient noise was as low as 31.6dBA which equals a totally quiet apartment at night. The measurements were performed at a distance of 1 meter from the system case. I also measured the level of noise at a distance of 3 centimeters from each noise source.

First of all I wanted to check out the level of noise at a distance of 1 meter from the closed testbed by turning on each of its components one by one.

1. The MGE Magnum 500 with its 80mm fan started up first. The PSU’s stock fan had proved to be very noisy and I had replaced it with an 80mm SilentBlade fan from GlacialTech with a specified speed of 1700rpm and a noise level of 19dBA.
2. Next, the 320GB hard drive from Hitachi (HDT725032VLA360, SATA-II, 7200rpm) was connected.
3. Next, the Thermaltake Extreme Spirit II chipset cooler was attached to the mainboard. Its fan has a specified speed of 4500rpm. I thought it noisy when I replaced the passive heatsink with this cooler, so I connected the fan via a resistor to achieve a speed of 2500rpm.
4. Then, the CPU cooler was connected. When measuring the overall noise from the system case the CPU had a Spire Fourier IV cooler with its 92mm fan rotating at 1750rpm.
5. 120mm system fans were connected after that: two 1180rpm fans from Cooler Master working for intake and exhaust and a side-panel 1000rpm Sharkoon Luminous Blue LED. The intake and exhaust fans hang on soft rubber pins from Noctua fans and have no immediate contact with the case.
6. Finally, I measured the noise from the DVD drive when copying one large file and from the HDD when testing its average access time.

The graphics card was equipped with a passive cooler so I didn’t measure its noise.

Here are the results:

Subjectively, the level of 36-37dBA seems to be the comfortable limit.  The fan on the side panel of the system case produces a sort of a rumble notwithstanding its low speed (1000rpm) – this can be seen in the noise level graph above. A curious thing, the noise of a single click of a Logitech M-BA47 mouse is as loud as 45.5dBA as measured from a distance of 55 centimeters. :)

And the following diagram shows the level of noise of each tested cooler as measured at a distance of 1 meter from a closed and fully functional system case (with the side-panel fan turned off) as well as at a distance of 3 centimeters when the CPU cooler was the only operating thing. The comfortable level of 36-37dBA is marked with a dashed line in the diagram.

I guess the diagram makes everything clear. Subjectively, coolers with a noise level of below 38dBA are audible, although not loud. The fan under the Fourier IV heatsink is really quiet (35.4dBA) while the other coolers can be heard. The Fourier IV is also the loudest cooler when it is working at its max speed of 3280rpm in a closed system case.

Although the 120mm fan of the Fourier III cooler has a rotation speed higher than that of the Thermaltake Big Typhoon by about 100rpm, its noise level is somewhat lower inside a system case. This must be due to the position of the fan under rather than above the heatsink. But the Big Typhoon is the quietest cooler in this test when measured from a distance of 3 centimeters.