Although similar in functionality to the more expensive Chieftec BPS-650C, the Chieftec CTG-650C can’t match the latter’s electrical specs. The load capacity of the +12V rail is almost 100 watts lower than the PSU’s full output power, and it can only work on 230V mains notwithstanding its active power factor correction.
The Chieftec CTG-650C lacks 80 PLUS certification because consumer-class PSUs are only certified for 115V mains, but the manufacturer claims that its peak efficiency is over 85%.
Working together with our APC SmartUPS SC 620, the PSU was stable at loads up to 382 watts when powered by the mains but could only switch to the UPS’s batteries at a load of 280 watts.
Cross-Load Voltage Stability
The main +12V voltage is far from stable, barely staying within the permissible range at low loads. Moreover, the PSU was unstable at zero loads on the +12V rail (which is hardly possible in a real-life computer, though). You can also note that the +12V voltage gets better as the computer consumes more from the +12V rail, being within 1% of the required level at near-maximum loads.
The two other voltages remain within 3% of the required levels (the +3.3V voltage goes out of this range at minimum loads only). That’s a good result considering the price of the PSU. Its overall performance in this test is quite satisfactory.
Output Voltage Ripple
The high-frequency voltage ripple isn’t strong, yet there are spikes on each power rail which may go out of the permissible range.
The same goes for the low-frequency voltage ripple except that there are fewer voltage spikes here.
Temperature and Noise
The PSU is cooled by a 120mm 7-blade Globe Fan S1202512L which has a rated speed of 2000 RPM and runs on a sleeve bearing.
The fan starts out at below 800 RPM and maintains that speed until a load of 230 watts. Then it accelerates linearly, reaching 1700 RPM at full load. The fan is audible at 1000 RPM and 330 watts and becomes downright uncomfortable at 1300 RPM and higher (or at loads of 500 watts).
Overall, the Chieftec CTG-650C is average in noisiness at high loads and quiet at medium loads.
Efficiency and Power Factor
The Chieftec CTG-650C is 84.3%, 87.2% and 83.3% efficient at the reference loads of 20%, 50% and 100%, respectively. It shows its peak efficiency at 50% load, thus delivering on the manufacturer’s promise of 85+. Overall, its efficiency is similar to many PSU models we’ve seen which have 80 PLUS Bronze certification.
The power factor is about 98% at full load, which is typical of PSUs with active power factor correction.
There are no problems with the standby source.
The Chieftec CTG-650C offers good electrical parameters and semi-modular design at a very affordable price. Its +12V voltage might be more stable and it might have weaker output voltage ripple, yet there are quite a lot of much more expensive PSUs that have the same downsides.