Five Highly Efficient Power Supplies: 1200 W and Up

Until recently, buying a PSU with a four-digit wattage was perhaps most useful for boasting among fellow hardware enthusiasts – there was barely any real need for such high wattages. However, Bitcoin mining and Altcoin mining have changed that.

Often, the requirements imposed on a product contradict each other or force the designers to find a middle ground: A high-wattage power supply achieving extremely high efficiency seems as unlikely as a sports car achieving 50 miles per gallon. However, the five PSUs in our test claim to do just that – one of them, the Corsair AX1500i, even specifies 90 to 94 percent efficiency at 1500 W sustained power. This power supply is the first power supply in our lab which is adorned by the 80 Plus Titanium logo – currently, there is no better rating. However, this impressive combination of power and efficiency comes at a hefty price: $450, almost twice what some Platinum-grade 1200 W PSUs command. Thus, if your use case doesn’t demand 1500 W or Titanium efficiency, you may be better advised to acquire a Platinum-grade 1200 W or 1300 W PSU. We included three of them in this test: The $280 Antec HCP-1300 Platinum, the $245 Cooler Master V1200, and the $270 Seasonic Platinum-1200. The fifth PSU in this test once again sports 1500 W, but at ‘merely’ Platinum efficiency: The Enermax Platimax EPM1500EGT, which doesn’t seem to be available in the U.S. yet.

But let’s return to the question: Who even needs such a powerful PSU? Average desktop PCs only need a 400 W PSU, if that. Some PCs even come with inexpensive 300 W PSUs. Even a high-end gaming rig typically doesn’t need more than a 750 W PSU, unless it contains multiple graphics cards. Using multiple graphics cards in a gaming PC is, however, a rare occurrence, as modern graphics cards are sufficiently powerful even for the most demanding games – there is simply no need for combining graphics cards via Nvidia’s SLI or AMD’s CrossFire. However, the demand for PSUs with more than 1000 W went through the roof during the past few months, and the reason is Bitcoin mining and Altcoin mining. Altcoin mining, by and large, still relies on graphics cards, although the first Scrypt ASICs are now available. However, Bitcoin mining rigs have not been based on graphics cards for more than a year – instead, these rigs are based on dedicated Bitcoin mining ASICs, whose DC-DC converters draw plenty of amps at 12 V. Enermax confirmed that the Platimax 1500 is flying off the shelves, and the same goes for all other high-wattage PSUs.

Lab Note: 80 Plus Certification at 230 V

Up till now, the 80 Plus organization Ecova Plug Load Solutions has been certifying PSUs at 115 V input voltage. 230 V-only PSUs were not eligible for the coveted 80 Plus certificate – conducting the test at 230 V would favor 230 V PSUs, as primary side currents, and by implication also resistive losses, are lower at 230 V. However, the certification agency recently introduced 80 Plus 230 V logos, whose efficiency thresholds are slightly more stringent, taking the higher efficiency of 230 V PSUs into account. That said, none of the PSUs in this round-up test, not even the 230 V-only Enermax Platimax, sported the new logo. Perhaps the 80 Plus 230 V logo is just too new.

Technical Specifications