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Five Highly Efficient Power Supplies: 1200 W and Up

Enermax Platimax 1500 EPM1500EGT

Several times already we have included Enermax Platimax PSUs in various round-up tests, and they always impressed us. Enermax sent us the 230 V version of the Platimax 1500, but a 115 V version should be released shortly. Strictly speaking, a 230 V–only PSU may not carry the 80 Plus Platinum logo, only the newly created 230 V version of this logo. This may be the reason why Enermax didn’t try to have the Platimax 1500 certified. At 5 years, the warranty period of this PSU is the shortest in this test – the four other PSUs offer 7 years warranty.

Like other Platimax models, the flagship model sports a nicely built case with roughened surfaces. At a depth of 7.9”, it is also the smallest case in this round-up test – an amazing feat for a 1500 W PSU. By the way, only the flagship model and the 1350 W model have fully modular cabling. While the motherboard cable and both CPU cables are round, all other cables are flat. There are ten PCIe connectors and 14 SATA plugs – impressive numbers, but in this high-end test field only average. The cable lengths are more or less OK, except for the PCIe cables, which are only 20” long.

While Cooler Master, Corsair, and Seasonic embrace the single rail design, the Enermax supply sports 6 (six!) 12 V rails, each of which can supply up to 30 A. This is less than a quarter of the 125 A on the 12 V rail of the Corsair AX1500i. While a fire inspector may favor the 30 A limit, hardware enthusiasts might feel confined by it. We try not to judge, but we deem short circuits and PC fires unlikely.

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AC Input220-240V, 50-60 Hz
DC Output+3.3V+5V+12V (#1)+12V (#2)+12V (#3)+12V (#4,5,6)-12V+5Vsb
24 A24 A30 A30 A30 A30 A0.5 A3 A
Individual Output32 A6 W15 W
Rail UtilizationSysSysCPU & VGA
Combined Output120 W1500 W
Total Continuous Output1500 W
Peak Output1650 W

Efficiency According to the 80 PLUS Spec

Efficiency for Typical Use Cases

Since the Platimax 1500 PSU only supports 230 V, it is not eligible for the 80 Plus Platinum logo and we didn’t hold it up to the Platinum standard, either. However, we did compare its efficiency at 230 V to other PSUs at 230 V. At low loads, its efficiency numbers are excellent: At 10% load, it achieves 88.7% efficiency. However, at full load, 88.9% is slightly lower than the requirement of the Platinum standard, while the 230 V input voltage should actually help the PSU in making the numbers. Below 10% load, its efficiency drops precipitously – only the Antec HCP-1300 comes in worse. The other test results are OK, but we think that a hold-up time of a mere 18.5 ms is a tad short. However, this value does comply with the ATX spec. Ripple and noise values are OK, but not as good as the excellent values exhibited by the Antec and Corsair PSUs.

The PSU fan’s sound level, however, is a clear opportunity for improvement. We don’t mind that the fan is always on – the Antec HCP-1300 has shown that this is not a problem. No, the Enermax PSU’s fan is simply too noisy. At a mere 40 W power draw, it generates 34.7 dB(A), which is already quite audible in a quiet room. But at 600 W power draw, the fan’s sound level increases to an annoying 40.5 dB(A).

A Closer Look at the PCB

While most manufacturers position the APFC and the primary side of the PSU on the left side and the secondary side on the right, Enermax rotated this layout by 90 degrees and put the primary side at the front and the secondary side at the rear. Enermax expects better cooling performance from this change, and we concur. Apart from this layout change, the electrical design of the PSU is similar to its competitors, and Enermax uses premium components – the primary side capacitors are sourced from Panasonic, and the secondary side ones are manufactured by Rubycon. The soldering quality is good, but there is some room for improvement.