Efficiency and PFC




Looking at the efficiency the first time, we actually couldn't believe the results and ran all our tests again. Unfortunately, the testing is correct and the efficiency is as you see above. Particularly at lower loads, the Zeus 1200W isn't that great, but that's not a huge concern as most buyers likely don't intend to use it with less than 300W of power. This power supply was made for maximum power setups and we don't expect stellar results at lower loads. Anyone even considering this power supply should plan on a minimum of 300W power draw - perhaps on servers or workstations that are rarely idle. As the graph shows, the best efficiency is reached with a power draw of 500W to 600W. If the goal is to stay in the 80% or higher efficiency range, 230VAC users will get this with power draws ranging from around 300W up to 1100W; 120VAC efficiency is quite a bit lower and only reaches 80% or higher in the 400W to 800W range, and 90VAC doesn't even break into the 80%+ efficiency range.


The power factor correction does very well, especially with lower input voltages. We haven't seen such a good result for a long time. 230CAV users will need to be happy with average results of up to .975.

DC Outputs and Quality Fan Speed and Acoustics
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  • BustedSony - Monday, July 7, 2008 - link

    Electrical work is expressed in terms of POWER. DC power uses Watts as the unit. Watts = Voltage times Amps. Thus with perfect efficiency 120 watts can be obtained EITHER with 12 volts at a 10 amp load, or 120 volts at a 1 amp load.

    Thus 12 volts running 100 amps = 1200 Watts. 120 volts running just 10 amps also equals 1200 watts. The difference in power available versus power drawn from the wall is loss of efficiency, generated mostly as heat.

    According to Ohms law current (amps) = voltage divided by resistance. Thus 10 amps would be drawn by 120 volts across 12 Ohms, or 12 volts across 1.2 Ohms.
  • mattclary - Monday, July 7, 2008 - link

    Ahhhhhh, thank you! At one time I knew Ohm's law, but had forgotten the role voltage played!
  • RamarC - Monday, July 7, 2008 - link

    will other manufacturers start using the deity naming scheme? are the Corsair Ra and OCZ Shiva next?
  • yacoub - Monday, July 7, 2008 - link

    No dude, Zeus is purposeful: He carries a lightning bolt. See the line Samuel L. Jackson delivers in Die Hard 3.
  • Merman - Monday, July 7, 2008 - link

    [quote]The quality of each rail is also surprisingly good. Ripple on the lower voltage rails doesn't reach higher than 4mV, and the 12V rails don't reach more than 12mV even with full load. At lower loads, the 12V rails are also around 4 to 8mV which is a very good result.[/quote]

    Finally talking about power quality again.

    Considering the ATX12V specification is a maximum of 120mV peak to peak is this result not outstanding and probably the best available on the market???

    Or is there a discrepancy in measurment with ATX specifications???

    It would be nice to compare ripple results from this site with the other top power supply review sites.

    If for some reason this is not possible please educate us rather than take the position that most don't understand this subject nor care.



  • C'DaleRider - Monday, July 7, 2008 - link

    I still find those ripple/noise generation findings a bit on the fantastic side. If they are what are represented, this means it blows PCP&C's best out of the water for controlling ripple and noise generation at full output.

    But, while Impervio is good at power supply manufacture, and this was made by Impervio, not Enhance as stated in the article, I sincerely doubt it actually measured only 12mV at full load and only 4-8mV otherwise on the +12V rails. Those figures are just too damned fantastic to be real. And to call them only "good"? They should have been labeled "The best" or "fantasy".
  • Christoph Katzer - Monday, July 7, 2008 - link

    Impervio doesnt have own production facility and produces at Enhance instead.
  • Christoph Katzer - Tuesday, July 8, 2008 - link

    This unit is made by IS Quasar. A factory with several robotic assemblers in Taiwan. Almost all of the Silverstone models we reviewed so far came from there.
  • Adamantine - Monday, July 7, 2008 - link

    Or could label them as "godly".
  • coolsam2 - Monday, July 7, 2008 - link

    first to post a comment.. sry 4 wasting u precious 2 seconds..

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