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 Rigol DS2072A oscilloscope kindly sponsored by Batronix, a Picoscope 3424 oscilloscope, a Picotech TC-08 thermocouple data logger, two Fluke multimeters (models 289 and 175), 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 three more oscilloscopes (Rigol VS5042, Stingray DS1M12, and a second Picoscope 3424), and a Class 1 Bruel & kjaer 2250-L G4 Sound Analyzer which is equipped with a type 4189 microphone that features a 16.6 - 140 dBA-weighted dynamic range. You will find more details about our equipment and the review methodology we follow in this article. We also 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 Load Regulation

The following charts show the voltage values of the main rails, recorded over a range of 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 four parallel bulk caps managed to achieve a hold-up time of over 16 ms, which is easier said than done considering the unit's huge capacity.

Inrush Current

Inrush current or switch-on surge refers to the maximum, instantaneous input-current drawn by an electrical device when it is first turned on. Because of the charging current of the APFC capacitor(s), PSUs produce a lot of inrush-current right as they are turned on. A lot of 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 a PSU's inrush current right as it is turned on, the better.



Given the combined capacity of all bulk caps, registered inrush current was on the low side.

Load Regulation and Efficiency Measurements

The first set of tests revealed the stability of the voltage rails and the efficiency of the G2-1600. The applied load was equal to (approximately) 10%-105% of the maximum load the PSU can handle, in 10% steps. We usually go up to 110%, but we sought to play it safe given this unit's huge capacity and only put the unit through an additional 80 W instead of 160 W.

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.


For starters, load regulation was amazing on all rails, a great accomplishment given the G2-1600 did so over its entire 1.6 kW range! Even the unit's 5VSB rail took the crown there. The PSU also had no problem whatsoever in delivering more than its full power at a very high ambient temperature, which clearly shows what it is capable of. Look at the corresponding column in the table above, though, and you will notice that there is no semi-passive mode because the platform lacks the heatsinks to accommodate one. It is a step behind the Corsair AX1500i in that regard, but we don't mind the lack of a semi-passive operation. On the contrary, we actually prefer it if the fan is constantly rotating slowly while internal temperatures aren't high to stave off internally high temperatures which could significantly influence the longevity of such components as electrolytic capacitors. Yet someone could easily argue that the G2-1600's fan is noticeable at even low speeds as its RPM actually isn't that low while the unit operates at normal temperatures. So its noise output throughout its entire load range is the only negative we were able to pin point in these tests. Fan speed varied a lot, but was unfortunately high during even the 10% load test, so the fan is noisy at even low speeds.