CNPS10X Extreme: Zalman's Extreme Makeover

Cooling
Viewing page 5 of 7 pages. Previous 1 2 3 4 5 6 7 Next

TEST RESULTS

Stock Fan Testing

The stock fan is a double ball bearing PWM model with translucent blades. One of the struts points directly upward contrary to the other three — this may help break up any tonality generated by the fan.


Stock Fan Specifications
Manufacturer Zalman Power Rating 4.8 W
Model Number ZF1125BTH Airflow Rating ?
Bearing Type Double ball bearing RPM Rating 1000~2150 RPM +/- 10%
Hub Size 42.7 mm Noise Rating 20.0~39.0 dBA
Frame Size 120 x 120 x 25 mm Header Type 4-pin PWM
Weight 130 grams Starting Voltage 5~6V (varies)
The data in the blue cells is provided by the manufacturer; we measured the data cited in the green cells

TEST MEASUREMENTS
Voltage
Noise Level
Speed
12V
37 dBA
2180 RPM
9V
31 dBA
1730 RPM
8V
27 dBA
1560 RPM
7.5V
15 dBA
1130 RPM
7V
12 dBA
680 RPM
6V
11~12 dBA
550 RPM
5V
11 dBA
410 RPM

Regular readers will notice that the measurement points are not at the usual 12, 9, 7 and 5 volts. This PWM fan, like many others, does not have as linear a relationship with voltage as normal DC fans. Between 9V and 7V, there is a huge drop in fan speed, which required finer voltage gradations to be tested.

Fan @ 12V: Extremely loud, turbulent, and whiny.

Fan @ 9V: Buzzy with a low-pitched hum. Still too loud at 31 dBA.

Fan @ 7.5V: Smooth with only a touch of hum. Fairly quiet at 15 dBA.

Fan @ 7V: Still smooth and almost inaudible from one meter's distance. Very little bearing noise.

Fan @ 5V: Inaudible except at close proximity.

The stock fan was too loud between 12V and 8V, but between 8V and 7V, there is a huge drop in fan speed resulting in some serious acoustic improvement. The hum breaks down and the motor emits only a very slight rattle. At lower speeds, it is surprisingly pleasant and smooth. On previous Zalman heatsinks, the fan's impeller was always mounted on thin pieces of metal so it could be integrated into its "flower" design. A fan with a proper frame doesn't vibrate nearly as much and it makes worlds of difference.

Fan Controller Modes
Mode
Est. Equivalent Voltage
RPM
Red
12V
2180
Purple
11V
2000
Blue
7.8V
1450
Green (Manual)
7.3V to 12V
1010~2190

The included fan controller has three different set modes that run the fan at 2180, 2000 and 1450 RPM. Manual mode allows it to spin at an approximate minimum speed of 1000 RPM which is a fairly quiet level.

(Editor's Note: This fan is highly significant in that it is the very first from Zalman not to have the buzzy ball-bearing sound so characteristic of all previous Zalman fans. For a brand which has long emphasized low noise as a key feature, Zalman fans have been notoriously bad sounding. This new fan finally breaks tradition. It's almost worthy of a halleluja!)



Previous 1 2 3 4 5 6 7 Next

Cooling - Article Index
Help support this site, buy from one of our affiliate retailers!
Search: