Primary Rails Load RegulationThe following charts show the voltage values of the main rails, recorded over a range from 60 W to the maximum specified load, and the deviation (in percent) for the same load range. Tight load regulation is an important PSU characteristic since it allows for constant voltage levels even with changes in load.
Hold-up TimeHold-up time represents the amount of time, usually measured in milliseconds, a PSU can maintain output regulations as defined by the ATX specification without input power. Hold-up time is the amount of time the system can continue to run without shutting down or rebooting during a power interruption. In the following screenshots, the blue line is the mains signal and the green line is the "Power Good" signal, while the yellow line represents the +12V rail.
Inrush CurrentInrush current, or switch-on surge, refers to the maximum instantaneous input current drawn by an electrical device when it is first turned on. Large enough inrush current can cause the tripping of circuit breakers and fuses and may also damage switches, relays, and bridge rectifiers. As a result, the lower the inrush current of a PSU right as it is turned on, the better.
10-110% Load TestingThese tests reveal the SDA2-650's load regulation and efficiency levels under high ambient temperatures. They also show how the fan-speed profile behaves under tough operating conditions.
|Load Regulation & Efficiency Testing Data - FSP SDA2-650|
|Test||12 V||5 V||3.3 V||5VSB||Power|
|Efficiency||Fan Speed||PSU Noise||Temp|
|10% Load||3.582A||1.989A||1.996A||0.985A||64.935W||84.044%||1643 RPM||24.8 dB(A)||40.45°C||0.877|
|20% Load||8.149A||2.984A||2.996A||1.185A||129.462W||89.285%||1649 RPM||24.8 dB(A)||40.62°C||0.950|
|30% Load||13.114A||3.482A||3.481A||1.387A||194.568W||91.078%||1744 RPM||27.1 dB(A)||41.34°C||0.972|
|40% Load||18.087A||3.983A||3.997A||1.590A||259.812W||91.577%||2307 RPM||35.1 dB(A)||41.52°C||0.982|
|50% Load||22.729A||4.981A||5.000A||1.795A||325.102W||91.580%||2742 RPM||40.9 dB(A)||42.16°C||0.988|
|60% Load||27.315A||5.983A||6.007A||2.001A||389.620W||91.040%||3416 RPM||47.1 dB(A)||42.80°C||0.991|
|70% Load||31.972A||6.988A||7.012A||2.209A||454.949W||90.723%||3505 RPM||48.6 dB(A)||43.09°C||0.993|
|80% Load||36.637A||7.995A||8.022A||2.418A||520.249W||90.271%||3493 RPM||48.6 dB(A)||43.68°C||0.994|
|90% Load||41.691A||8.503A||8.511A||2.423A||585.177W||89.836%||3492 RPM||48.6 dB(A)||44.10°C||0.996|
|100% Load||46.708A||9.010A||9.037A||2.531A||649.910W||89.248%||3490 RPM||48.5 dB(A)||45.69°C||0.997|
|110% Load||52.139A||9.018A||9.039A||2.537A||714.727W||88.606%||3489 RPM||48.5 dB(A)||46.56°C||0.997|
|Crossload 1||0.153A||14.002A||14.000A||0.000A||117.317W||83.143%||3156 RPM||44.5 dB(A)||42.68°C||0.948|
|Crossload 2||54.018A||1.004A||1.000A||1.000A||664.212W||89.805%||3492 RPM||48.6 dB(A)||45.25°C||0.997|
Light Load TestingIn the following tests, we measure the SDA2-650's efficiency at loads significantly lower than 10 percent of its maximum capacity (the lowest load the 80 PLUS standard measures). This is important for when a PC is idle with its power-saving features turned on.
|Efficiency at Low Loads - FSP SDA2-650|
|Test #||12 V||5 V||3.3 V||5 VSB||Power|
|Efficiency||Fan Speed||PSU Noise||PF/AC |
|1||2.848A||0.496A||0.482A||0.196A||39.583W||81.559%||0 RPM||<6.0 dB(A)||0.690|
|2||4.106A||0.993A||0.995A||0.392A||59.985W||84.682%||1644 RPM||24.8 dB(A)||0.864|
|3||5.298A||1.491A||1.480A||0.589A||79.479W||86.925%||1645 RPM||24.8 dB(A)||0.903|
|4||6.555A||1.989A||1.994A||0.787A||99.875W||88.296%||1648 RPM||24.8 dB(A)||0.929|
EfficiencyUsing the results that we gathered so far, we plotted a chart showing the SDA2-650's efficiency at low loads and loads ranging from 10 to 110 percent of its maximum-rated capacity.
Efficiency with light loads is high enough. With normal loads, the unit falls behind the competition, though. As you can see in the graph above, FSP's other platform, used in the EVGA 650 GM, performs much better.
|5VSB Efficiency - FSP SDA2-650|
|Test #||5VSB||Power (DC/AC)||Efficiency||PF/AC Volts|
The 5VSB regulator needs upgrades for improved efficiency. FSP has highly efficient 5VSB regulator circuits, which has me wonder why its engineers used this one.
Power Consumption in Idle and Standby
|Idle / Standby - FSP SDA2-650|
|Mode||12 V||5 V||3.3 V||5VSB||Power (AC)||PF/AC Volts|
Fan RPM, Delta Temperature and Output NoiseThe following results were obtained at 37–47 °C ambient.
The following results were obtained at 30–32 °C ambient.