Corsair CX Series Modular CX600M 600 W Review 19

Corsair CX Series Modular CX600M 600 W Review

Efficiency, Temperatures & Noise »

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, and 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 40-45°C ambient in order to simulate with higher accuracy the environment seen inside a typical system, with 40-45°C being derived from a standard ambient assumption of 23°C and 17-22°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 60W 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

The hold-up time is a very important characteristic of a PSU and represents the amount of time, usually measured in milliseconds, that a PSU can maintain output regulations as defined by the ATX spec without input power. In other words, it is the amount of time that the system can continue to run without shutting down or rebooting during a power interruption. The ATX spec 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 small hold-up cap, which is there as a result of the low-budget production cost, led to a very low hold-up time below 10 ms. Very bad performance here for the CX600M, but a bulk cap of a higher capacity would, unfortunately, cost significantly more, especially if it were a Japanese cap like the one in this unit.

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 they are turned on, the better.

Very low inrush current, which is good but due to the small bulk capacitor. This clearly shows that a bad thing can in some cases produce good results (something similar to the Chinese yin-yang concept).

Voltage Regulation and Efficiency Measurements

The first set of tests revealed the stability of the voltage rails and the efficiency of the CX600M. The applied load was equal to (approximately) 20%, 40%, 50%, 60%, 80%, 100%, and 110% of the maximum load that 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 2 A. In the second test, we dialed the maximum load that the +12V rail could handle while the load on the minor rails was minimal.

Voltage Regulation & Efficiency Testing Data
Corsair CX600M
Test12 V5 V3.3 V5VSBPower
EfficiencyFan SpeedFan NoiseTemp
20% Load8.184A1.960A1.986A1.005A119.75W87.24%777 RPM31.0 dBA 38.66°C0.891
11.998V5.089V3.318V4.971V137.27W 41.98°C229.9V
40% Load16.776A3.938A3.994A1.210A239.71W88.65%1185 RPM36.8 dBA 39.65°C0.954
11.956V5.068V3.302V4.951V270.39W 43.42°C229.9V
50% Load20.982A4.938A5.007A1.620A299.73W88.15%1458 RPM39.3 dBA 41.21°C0.967
11.927V5.060V3.294V4.936V340.04W 45.58°C230.0V
60% Load25.204A5.931A6.024A2.030A359.69W87.67%1700 RPM42.2 dBA 42.84°C0.974
11.901V5.051V3.286V4.918V410.29W 47.81°C229.9V
80% Load33.849A7.944A8.071A2.450A479.57W86.53%1920 RPM45.2 dBA 44.61°C0.981
11.854V5.030V3.268V4.894V554.20W 51.06°C229.9V
100% Load43.313A8.948A9.127A3.078A599.57W84.99%1920 RPM45.2 dBA 45.28°C0.986
11.773V5.026V3.253V4.868V705.45W 53.27°C229.9V
110% Load48.583A8.941A9.142A3.082A659.48W84.26%1920 RPM45.2 dBA 45.77°C0.988
11.729V5.030V3.248V4.861V782.65W 54.41°C229.9V
Crossload 11.966A16.012A16.004A0.502A156.47W78.76%1975 RPM45.6 dBA 42.25°C0.934
12.376V4.815V3.284V4.952V198.66W 47.60°C230.1V
Crossload 245.963A1.000A1.003A1.001A541.92W86.25%1895 RPM45.0 dBA 43.25°C0.983
11.498V5.218V3.279V4.928V628.30W 49.48°C230.0V

As you can see, we managed to make the unit deliver more than its full power at over 45°C, regardless of the narrow operating temperature range that Corsair gives for full continuous power output. The unit did, however, shut down at about 47°C, and we had to wait a couple minutes for it to cool down before we were able to power it up again. Over temperature protection (OTP) apparently kicked in to keep the PSU from overheating. Regarding its performance, the CX600M registered quite good voltage regulation on all rails for its category, since it managed to keep all of its rails significantly below the 3% mark. The fan was also very quiet during the first two tests, and only afterwards did it start operating at increased speeds, reaching its maximum RPM with the 80% load. Overall efficiency was high and peaked at 88.65% with the 40% load, a pretty high reading for a mere Bronze unit.
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