Enermax Platimax 750W - 80 Plus Platinum Arrivesby Martin Kaffei on February 10, 2012 6:00 PM EST
The Enermax Platimax 750W is a very efficient and expensive power supply. There are no significant disadvantages with the design and technology, though you'll have to pay for the privilege. The connector configuration is very good, and both the choice of components and the power supply case are very high quality. Enthusiasts looking for great performance will find this power supply a suitable solution.
Internally, Enermax uses a modified Modu87+ design with better semiconductors. The PCB material and the electrolytic capacitors in this PSU are top quality parts. The output side of the resonant converter is complemented by full-wave synchronous rectification (with MOSFETs), minimizing switching losses and the voltage drop the Schottky diodes usually have. There are a few other smaller changes as well, such as the buck converter for -12V and the "improved" EMI filtering with fewer components. We mentioned the low power output on the +3.3V and +5V rails, but this is not necessarily a disadvantage. As always, the required power depends on the system.
A modern PC pulls the majority of the current from the +12V output(s), so it's not so much the quantity but the quality of the smaller outputs that is important. Some sensitive logic gates on the motherboard need a stable 3.3V output but only low currents. The voltage drop under high load is negligible and is simply a reflection on the sizing of the converters. A low output ripple and noise is more decisive. During the load test +3.3V drops to a minimum of -3.63% below the reference value while +5V drops by as much as -2.4% to -2.60% during overload.
Even at 10% load the Platimax 750W reaches 86.93% efficiency, a remarkable value. The power factor is also very high. Low ripple and noise on most output voltages is advantageous as well. With 0.9% ripple (1% is allowed) +3.3V is the worst output. We would like to see better results here, since this is a high-end product. Apart from that the Platimax hardly blinks when confronted with our crossload tests. The voltages are always very close to their ideal value. If you don't put too many amps on +5V and +3.3V, you might even say Enermax shows flawless results.
In any case the noise of the fan is impeccable. Enermax has promised to use a low speed regulation for the Twister fan, which is true. Apart from the audible noise under full load the PSU is always nearly silent. There's also no noise from the electronics (not that we would expect anything less from a high-end PSU).
Enermax delivers an adequate cable configuration, similar to what other manufacturers offer. Four 6/8-pin PEG and 16 peripheral connectors are fairly average in this performance class, as are the 4+4-pin and 8-pin connectors for CPU power. The colorful sleeving can be described as high-grade (even if gold and red is the "wrong" color for this PSU) , and the contents of the package are satisfying. For the larger Platimax models you can even get a case fan for free. Enermax offers everything you might want from a PSU, with a few extras just for good measure.
The Platimax series includes 600W, 750W, 850W, 1000W, and 1200W models—and several of the lower wattage models have mail-in rebates available, if you're interested. The 750W we're reviewing can currently be had for $200, with a $30 MIR bringing the cost down to just $170. The largest competition for the 750W Platimax might just be Enermax's own Modu87+ 700W, which has a lower base price of $180 but no MIR. According to our research that model is not fundamentally different and is sometimes (depending on rebates) cheaper. However, when we are talking about power supplies, even small details make the difference.
Note that the only direct 80 Plus Platinum alternative comes from SuperFlower/Kingwin. The Kingwin LZP-750 (made by SuperFlower) is just as expensive as the Enermax Platimax 750W (slightly more, actually), and it's missing some features such as OCP, a MOV, and similar protections. Beyond that the LZP-750 (or SuperFlower Golden King Platinum—which is even worse than Platimax as far as names go!) offers fewer connectors. For that reason we would recommend the Platimax 750W, but only for those who demand every ounce of efficiency. If you're more of a mainstream user and can live with 1-2% less efficiency, you can certainly save some money, but it's clear that Enermax is a leading company for high-quality products.