Efficiency





Room Temperature

Since the design of the Liberty is a few years old, we didn't expect incredible results. The efficiency is not very high compared to our most recent models, though we did measure an efficiency of 81% maximum which would have been good 2 years ago. For the most part, efficiency is in the 75-80% range with loads of 20% to 80%.

Power Factor Correction


The PFC is very good at lower input voltages, while as usual we see worse results at 230VAC. Scores of .99 or higher are desirable, which the Liberty achieves on 115VAC. The 230VAC result is not unusual, and for a two year old model we won't complain too much. On higher-end PSUs we would like to see PFC break .99 at high loads even on 230VAC, but it's certainly not a bad result.

OCP Test

In the OCP test we use a function from the Chroma to see how much load each rail can take. The test puts on an additional 5A each second on the test rail until either the OCP kicks in or our Chroma will shuts down from overpowering.

OCP Test

The Liberty performed well on the two 12V rails. The OCP was based at the usual amount of 24A. The 3.3V rail kicked in quite early; instead of the promised 28A we could only reach 25A and at the 5V rail we could only reach 29A instead of 30A. This is not a critical flaw, however, since the performance during testing was still very good and the 12V rails tend to be much more important than the 3.3V and 5V rails.

12V DC Outputs Temperatures, Fan Speed, and Acoustics
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  • MCSim - Tuesday, July 31, 2007 - link

    400W Liberty here. Mine is also about 2 years old and still going strong. There's no need for new PSU. :)
  • wolfman3k5 - Monday, July 30, 2007 - link

    Just out of curiosity, did you guys run out of stuff to write about?
  • leexgx - Monday, July 30, 2007 - link

    heh


    i had the 400W Enermax PSU for 2 years now and its powering my server quite happy (8 hdds and an old P4 2.6ghz 2gb ram) never had an problem with them (use thermaltake TR2 420W-500w now for basic PSU as its the only good ones on my local trade lists never had one blow on me)
  • CuriousMike - Monday, July 30, 2007 - link

    fwiw, I bought two 350w enermax "basic" powersupplies about 2 years ago ( built two new machines for home.)

    One of the units fans developed a bad squeek about 2 months into ownership.
    I tried contacting enermax in two different ways - both via email.
    One was their usa (my locale) website (which I think was a distributor site?), and the other their taiwanese/chinese site.

    Never heard back from them.
  • JarredWalton - Monday, July 30, 2007 - link

    The squeaky PSU gets the new fan, and the squeaky wheel gets the oil. You just need to squeak a bit louder probably. That or you got unlucky. I haven't dealt with Enermax directly, but I have had a few companies (DFI, for example) where it took several email messages to get help. Not good at all, but eventually they did respond. The fact that their email support form fails 75% of the time didn't help, of course.
  • Vidmar - Monday, July 30, 2007 - link

    While I think the Efficiency charts in load percentage are nice, if you included Efficiency charts in watts it would be more informative from a buying perspective.

    The reason? I know the sum of system load is 375watts normally. The way it is now, if power supply XYZ has a max load of 650watts, I have to calculate where my ~375watts falls into that load chart (~57% load). But if the next power supply has 1000 watts max, then I have to yet again calculate what load percentage that may be for *that* power supply. If the Efficiency charts were in watts, instead of load, no calculations would be necessary. If I could look at your charts and see that XYZ power supply provided those watts the most efficiently, that would be the power supply I would get.

    Maybe you could just provide a second X axis on the chart that included the watts.

    Thanks!
  • michal1980 - Monday, July 30, 2007 - link

    Owned for for probably 18+ months now. It was a replacement for the early problems the antec neo-he's had. and I bought it at a retail store for about 110 bucks. I had no idea if it was good because it was so cheap (for a retail store, everyother branded 500w psu was 150~180 bucks).

    its given me good stable power for all these years, and I hope for a few more.
  • kmmatney - Monday, July 30, 2007 - link

    I've owned a 550W Enermax PSU for over 5 years! It was originally made for the old Thunder K7 dual AMD motherboards, but it now powers my Core 2 Duo. It's been a great power supply - never thought it would last so long. I did recently re-oil the fan (still running on the original fan as well).
  • mostlyprudent - Monday, July 30, 2007 - link

    Nice review. I appreciate the diversion from the high end. I have been wondering how newer models would stack up against an old favorite. It is nice to see that there is a little more happening in the PSU industry than just wattage hikes.
  • Thinkitect - Monday, July 30, 2007 - link

    Almost!

    Value PSU review? Quality Benchmarks? Fortron Source!

    FSP Group products should be the baseline for the reviews and price/performance rating.
    The AX-400 and AX-500 for value were great (and still are), though efficiency may be outdated. The blue series should be the one to compare to right now.

    I've used the same AX for years through many upgrades, and it now powers a relative's workstation. I have the BlueStorm II 500 powering my new gaming rig, and now there are the FX-600-GLN and FX-700-GLN with even higher efficiency ratings.

    High quality well priced components that deserve the comparison and recognition.

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