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Part 1: Four Cheap 80 PLUS Bronze Power Supplies, Reviewed

Chieftec Nitro 2 85+ BPS-550C2: Measurements

Efficiency According to the 80 PLUS Spec

Efficiency by Load

Chieftec's 550 W PSU comes out swinging, proving that spending a little more on a power supply can make a difference in the efficiency measurements. While it's only 80 PLUS Bronze-certified, it satisfies the efficiency requirements without breaking a sweat. In fact, it exceeds the Bronze standard's requirements by about two percentage points in all three categories, coming close to the Silver standard. On top of that, its standby power is the lowest of all test candidates; so is its inrush current. We repeated the inrush current metric several times to be sure, and the outcome did not change.

The hold-up time of the Chieftec PSU is also quite long at well over 20 ms (at 230 V, you're looking at a hold-up time of 24.6 ms without electricity). The ripple and noise values are within spec. They're not excellent, but within the ATX standard, which we consider to be OK. The PSU's sound level is average among the test candidates.

A Close Look at the PCB

After cutting open the riveted enclosure, we figured out that the OEM manufacturer is Channel Well Technology in Taiwan. The input filter is partially located on a separate PCB, adjacent to the mains socket. Here we find two Y capacitors and one X capacitor. Four additional Y capacitors sit on the main PCB, along with another X capacitor, a MOV, and three choke coils. The capacitors are manufactured by Nippon Chemi-Con. The soldering quality is OK.