OCZ Fatal1ty 750W PSU
4. Tests
For this test we monitored each of the rails of the PSU under various loads, which represent different power-hungry PC configurations. We took voltage measurements for 150W, 300W 450 W, 600W and finally 750W loads.
The current ATX specifications allow for the following fluctuations in voltage outputs:
- 3.3V Rail: 3.135V - 3.465V
- 5V Rail: 4.75V – 5.25V
- 12V Rail: 11.4V – 12.6V
An oscilloscope was also used to examining the voltage ripple on the rails using the proper capacitors in place to filter noise. This measures how clean the power delivery really is for the tested power supply. The ATX specifications' requirement for ripple is 120 mV for 12V and 50mV for the rest outputs.
The results is illustrated below:
Voltage regulation |
Efficiency |
Noise |
Ripple |
|||||
LOAD |
3.3V |
5V |
12V |
3.3V |
5V |
12V |
||
150W |
3.31 |
5.08 |
12.11 |
82.3% |
30dBA |
|||
300W |
3.30 |
5.01 |
12.05 |
81.8% |
30 dBA |
|||
450W |
3.31 |
4.99 |
12.02 |
84.9% |
33.1 dBA |
|||
600W |
3.30 |
4.98 |
12.01 |
85.4% |
35.6 dBA |
|||
750W |
3.29 |
4.98 |
11.94 |
83.2% |
42 dBA |
18.4mV |
21.9mV |
39.5mV |
Result |
OK |
OK |
OK |
OK |
OK |
OK |
OK |
As you see below, the voltage deviations as well as ripple for all the outputs were well within the acceptable limits.
AC ripple is decent for this Category of PSU and well within requirements.
Voltage regulation at +12V is good, although we would expect a better behavior of the minor rails.
Efficiency was also high for all the loads and exceeded the bronze spec.
Regarding noise levels, we measured any audible sound from a 1m distance from the PSU. The fan was silent until the 300W loads. A low 33.1dB(a) was measured after the 450W point and reached the 42dB(A) under full load, which is audible but still acceptable.