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 can deliver 2500 W of load, and all loads are controlled by a custom-made software. The AC source is a Chroma 6530 capable of delivering up to 3 kW of power. 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), a Keithley 2015 THD 6.5 digit bench DMM, and a lab-grade N4L PPA1530 3-phase power analyzer along with a Yokogawa WT210 power meter. We also included a wooden box, which, along with some heating elements, was used as a hot box and 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 we 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 more accurately, 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.

We use a GPIB-USB controller in order to avoid the Chroma 6530's very picky serial port. This controller was kindly provided by Prologix.



We use an OLS3000E online UPS with a capacity of 3000VA/2700W to protect our incredibly expensive Chroma AC source.

Primary Rails Load 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 its output regulation as defined by the ATX specification without input power. It is, in other words, the amount of time a 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.



Similar to the RM1000i, hold-up time was very long, which is as expected since both PSUs use the same bulk caps.

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 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 a PSU's inrush current right as it is turned on, the better.



We measured over 50 A inrush current with our shiny new power meter that is much more accurate than our old one. This reading is normal for a 1 kW PSU with the proper bulk caps for a hold-up time of 16 ms hold-up.

Load Regulation and Efficiency Measurements

The first set of tests revealed the stability of the voltage rails and the RM1000x's efficiency. The applied load was equal to (approximately) 10%-110% of the maximum load the PSU can handle, in 10% steps.

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.


Load regulation at +12V isn't that tight; however, it is still well within 2%. The minor rails, including 5VSB, are incredibly well regulated, well on par with the competition. The RM1000x is also very efficient for a Gold-certified PSU and dead silent at up to 50% of its maximum-rated capacity despite very high operating temperatures. Semi-passive mode lasted for quite a while with normal loads, which is key in keeping noise output low. A passive operation puts electrolytic caps under a lot of stress because of increased operating temperatures, but Corsair must have taken that into account since the unit comes with a seven year warranty.

We had to push the PSU beyond its limits with a 110% load to make its fan spin at full speed, which made it noticeable, although not by as much as with other PSUs of similar capacity. Corsair did a fine job in keeping the fan quiet, providing a nice combination of high performance, capacity, and output noise.