Efficiency
Using the efficiency results from the previous page, we plotted a chart showing efficiency of the FTY550W at low loads and at loads equal to 20%-110% of the PSU's maximum-rated load.
While efficiency at normal loads is close to that of other Bronze units with similar capacity, it is decent at low loads; that is, for the unit's characteristics and its category. All in all, the PSU registered decent efficiency for a Bronze unit, and that throughout its entire load range.
Efficiency at Low Loads
In the next tests, we measured the efficiency of the FTY550W at loads much lower than 20% of its maximum rated load (the lowest load the 80 Plus Standard measures). The loads we dialed were 40 W, 60 W, 80 W, and 100 W (for PSUs with over 500 W capacity). This is important for settings where the PC is in idle mode with Power Saving turned on.
Efficiency at Low Loads OCZ Fatal1ty 550W |
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Test # | 12 V | 5 V | 3.3 V | 5 VSB | Power (DC/AC) | Efficiency | Fan Speed | Fan Noise | PF/AC Volts |
1 | 1.832A | 1.951A | 1.958A | 0.190A | 39.74W | 73.11% | 1062 RPM | 38.9 dBA | 0.586 |
12.117V | 5.113V | 3.365V | 5.131V | 54.36W | 230.2V |
2 | 3.404A | 1.952A | 1.960A | 0.390A | 59.74W | 78.94% | 1095 RPM | 39.5 dBA | 0.688 |
12.093V | 5.120V | 3.361V | 5.118V | 75.68W | 230.3V |
3 | 4.989A | 1.952A | 1.962A | 0.583A | 79.75W | 81.82% | 1224 RPM | 41.3 dBA | 0.780 |
12.066V | 5.119V | 3.359V | 5.102V | 97.47W | 230.2V |
4 | 6.577A | 1.952A | 1.963A | 0.782A | 99.74W | 83.72% | 1268 RPM | 41.7 dBA | 0.863 |
12.039V | 5.119V | 3.356V | 5.089V | 119.14W | 230.2V |
Efficiency was pretty good at low loads; that is, for the specifications of this unit. Its small capacity also helped significantly in achieving good efficiency results.
5VSB Efficiency
The ATX spec states that 5VSB standby supply efficiency should be as high as possible and recommends 50% or higher efficiency with 100 mA of load, 60% or higher with 250 mA of load, and 70% or higher with 1 A or more of load.
We will take four measurements: one at 100, 250, and 1000 mA, each, and one with the full load the 5VSB rail can handle.
5VSB Efficiency OCZ Fatal1ty 550W |
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Test # | 5VSB | Power (DC/AC) | Efficiency | PF/AC Volts |
1 | 0.102A | 0.53W | 62.35% | 0.042 |
5.149V | 0.85W | 230.6V |
2 | 0.252A | 1.30W | 68.78% | 0.090 |
5.141V | 1.89W | 230.7V |
3 | 1.002A | 5.11W | 78.14% | 0.237 |
5.098V | 6.54W | 230.6V |
4 | 2.502A | 12.54W | 77.55% | 0.341 |
5.010V | 16.17W | 230.4V |
We don't have any complaints here since we have measured lower 5VSB efficiency results in even high-end PSUs. The only problem was the loose voltage regulation on this rail, which, however, won't seriously affect the devices this rail will feed.
Power Consumption in Idle & Standby
In the table below, you will find the power consumption and the voltage values of all rails (except -12V) when the PSU is in idle mode (powered on but without any load on its rails) and the power consumption when the PSU is in standby mode (without any load at 5VSB).
Idle / Standby OCZ Fatal1ty 550W |
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Mode | 12 V | 5 V | 3.3 V | 5VSB | Power (AC) | PF/AC Volts |
Idle | 12.003V | 5.209V | 3.380V | 5.083V | 8.86W | 0.171 |
230.7V |
Standby | 0.23W | 0.009 |
230.2V |
Phantom power was at almost half the limit of the ErP Lot 6 2013 directive, so this unit is ECO friendly.
Fan RPM, Delta Temperature & Output Noise
The cooling fan's speed (RPMs) and the delta difference between input and output temperature are illustrated in the following chart. The following results were obtained at 39°C-46°C ambient.
A chart that shows the cooling fan's speed (RPMs) and the output noise follows. We measure the fan's noise from 1 meter away, inside a small custom-made anechoic chamber whose internals are completely in specialized soundproofing material (
Be Quiet! Noise Absorber Kit). Background noise inside the anechoic chamber was below 30 dBA during testing and the results were obtained with the PSU operating at 39°C-46°C ambient.
The following graph illustrates the fan's output noise throughout the entire operating range of the PSU. The same conditions of the above graph apply to our measurements, but the ambient was between
28°C and 30°C.
As we expected from a Bronze unit, the Fatal1ty 550 W features a rather noisy operation which won't pass by unnoticed if your hearing is sensitive.