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
Test
12 V
5 V
3.3 V
5VSB
Power (DC/AC)
Efficiency
Fan Speed
Fan Noise
Temp (In/Out)
PF/AC Volts
20% Load
8.184A
1.960A
1.986A
1.005A
119.75W
87.24%
777 RPM
31.0 dBA
38.66°C
0.891
11.998V
5.089V
3.318V
4.971V
137.27W
41.98°C
229.9V
40% Load
16.776A
3.938A
3.994A
1.210A
239.71W
88.65%
1185 RPM
36.8 dBA
39.65°C
0.954
11.956V
5.068V
3.302V
4.951V
270.39W
43.42°C
229.9V
50% Load
20.982A
4.938A
5.007A
1.620A
299.73W
88.15%
1458 RPM
39.3 dBA
41.21°C
0.967
11.927V
5.060V
3.294V
4.936V
340.04W
45.58°C
230.0V
60% Load
25.204A
5.931A
6.024A
2.030A
359.69W
87.67%
1700 RPM
42.2 dBA
42.84°C
0.974
11.901V
5.051V
3.286V
4.918V
410.29W
47.81°C
229.9V
80% Load
33.849A
7.944A
8.071A
2.450A
479.57W
86.53%
1920 RPM
45.2 dBA
44.61°C
0.981
11.854V
5.030V
3.268V
4.894V
554.20W
51.06°C
229.9V
100% Load
43.313A
8.948A
9.127A
3.078A
599.57W
84.99%
1920 RPM
45.2 dBA
45.28°C
0.986
11.773V
5.026V
3.253V
4.868V
705.45W
53.27°C
229.9V
110% Load
48.583A
8.941A
9.142A
3.082A
659.48W
84.26%
1920 RPM
45.2 dBA
45.77°C
0.988
11.729V
5.030V
3.248V
4.861V
782.65W
54.41°C
229.9V
Crossload 1
1.966A
16.012A
16.004A
0.502A
156.47W
78.76%
1975 RPM
45.6 dBA
42.25°C
0.934
12.376V
4.815V
3.284V
4.952V
198.66W
47.60°C
230.1V
Crossload 2
45.963A
1.000A
1.003A
1.001A
541.92W
86.25%
1895 RPM
45.0 dBA
43.25°C
0.983
11.498V
5.218V
3.279V
4.928V
628.30W
49.48°C
230.0V
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.