Test Setup

All measurements were performed using two Chroma 6314A mainframes equipped with the following electronic loads: six 63123A [350 W each], one 63102A [100 W x2], and one 63101A [200 W]. The aforementioned equipment is able to deliver 2500 W of load, and all loads are controlled by a custom-made software. We also used a Picoscope 3424 oscilloscope, a Picotech TC-08 thermocouple data logger, a Fluke 175 multimeter, and a Yokogawa WT210 power meter. We also included a wooden box, which, along with some heating elements, was used as a hot box. Finally, we had at our disposal four more oscilloscopes (Rigol 1052E and VS5042, Stingray DS1M12, a second Picoscope 3424), and a CEM DT-8852 sound level meter. In this article, you will find more details about our equipment and the review methodology we follow. Finally, we conduct all of our tests at 40°C-45°C ambient to simulate the environment seen inside a typical system with a higher accuracy, with 40°C-45°C being derived from a standard ambient assumption of 23°C and 17°C-22°C being added for the typical temperature rise within a system.

Primary Rails Voltage Regulation

The 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.

5VSB Regulation

The following chart shows how the 5VSB rail deals with the load we throw at it.

Hold-up Time

Hold-up time is a very important PSU characteristic and represents the amount of time, usually measured in milliseconds, a PSU can maintain output regulations as defined by the ATX spec without input power. In other words, it is the amount of time the system can continue to run without shutting down or rebooting during a power interruption. The ATX specification sets the minimum hold-up time to 16 ms with the maximum continuous output load. In the following screenshot, the blue line is the mains signal and the yellow line is the "Power Good" signal. The latter is de-asserted to a low state when any of the +12V, 5V, or 3.3V output voltages fall below the undervoltage threshold, or after the mains power has been removed for a sufficiently long time to guarantee that the PSU cannot operate anymore.



The increased capacity of the unit's hold-up caps allowed it to take the lead from EVGA's identical unit. However, even the additional 120 µF capacitance didn't allow it to hit the 16 ms threshold. That said, we think the 15 ms to be very decent for a unit with such a high capacity. It is, after all, really hard to put a full load on a 1.3 kW PSU unless you use no less than three high-end VGAs for mining.

Inrush Current

Inrush current or switch-on surge refers to the maximum, instantaneous input-current drawn by an electrical device when first turned on. Because of the charging current of the APFC capacitor(s), PSUs produce large inrush-current right as they are turned on. Large 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.



Despite the higher overall combined capacity of the bulk caps, the Leadex unit registered marginally lower inrush current than the EVGA G2 1300 W. The NTC thermistor most likely helped here.

Voltage Regulation and Efficiency Measurements

The first set of tests revealed the stability of the voltage rails and the efficiency of the SF-1300F14MG. The applied load was equal to (approximately) 20%, 40%, 50%, 60%, 80%, 100%, and 110% of the maximum load the PSU can handle.

We conducted two additional tests. In the first test, we stressed the two minor rails (5V and 3.3V) with a high load while the load at +12V was only 0.10 A. This test reveals whether the PSU is Haswell ready or not. In the second test, we dialed the maximum load the +12V rail could handle while the load on the minor rails was minimal.

This PSU easily handled 130 W more load than its full nominal capacity and did so at a very high operating temperature that reached 47°C, which clearly shows that it can handle 1300 W continuously without any problems. However, once we pushed the PSU to its limits, the fan increased its speed, and output noise was then too high for even those without sensitive hearing. Yet this is very powerful PSU, so we shouldn't expect it to be quiet once fully stressed.

Every rail delivered excellent voltage regulation easily comparable to that of the competition. Super Flower did a great job in this section, managing overall tight voltage regulation and very high efficiency levels throughout the unit's entire load range. The unit scored over 90% efficiency on all tests except for the overload and CL1 ones, and we measured close to 93%, an impressive reading normally reserved for Platinum, not Gold units, at typical load.