FSP Twins 500W Redundant PSU Review

Reviews
By Aris Mpitziopoulos
published

The FSP Twins series combines the usability of a normal ATX PSU and the advanced features of a redundant server unit. The Twins 500W we're evaluating today addresses users that need an ultra-reliable PSU and are willing to pay for it.

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Ripple Measurements

To learn how we measure ripple, please click here.

The following table includes the ripple levels we measured on the Twins 500W's rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).

Swipe to scroll horizontally
Test12V5V3.3V5VSBPass/Fail
10% Load53.7mV13.7mV22.2mV12.5mVPass
20% Load53.1mV13.7mV22.0mV13.7mVPass
30% Load53.1mV13.5mV22.5mV13.7mVPass
40% Load53.9mV13.6mV22.5mV14.0mVPass
50% Load57.6mV13.5mV22.9mV14.5mVPass
60% Load61.7mV13.6mV23.2mV15.3mVPass
70% Load62.8mV13.5mV24.0mV15.8mVPass
80% Load61.5mV13.3mV23.8mV16.7mVPass
90% Load63.2mV13.4mV24.5mV16.9mVPass
100% Load63.8mV14.2mV25.8mV17.6mVPass
110% Load67.4mV14.3mV26.4mV18.0mVPass
Cross-Load 161.9mV15.7mV25.9mV15.2mVPass
Cross-Load 266.9mV15.3mV22.8mV16.0mVPass
Image 1 of 4

Ripple suppression at +12V isn't that good, but it's great on the 5V and 5VSB rails. It's decent at 3.3V, too.

Ripple Oscilloscope Screenshots

The following oscilloscope screenshots illustrate the AC ripple and noise registered on the main rails (+12V, 5V, 3.3V, and 5VSB). The bigger the fluctuations on the screen, the bigger the ripple/noise. We set 0.01 V/Div (each vertical division/box equals 0.01V) as the standard for all measurements.

Ripple At Full Load

Image 1 of 4

Ripple At 110-Percent Load

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Ripple At Cross-Load 1

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Ripple At Cross-Load 2

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Aris Mpitziopoulos
Contributing Editor

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

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17 Comments Comment from the forums
  • shrapnel_indie
    Pros

    Full power at 45°C
    All cables are fixed, and because this is a server-like product, its maximum operating temperature for continuous full power delivery is 50°C.


    Please explain to me why these numbers don't seem to match up properly. (THB, I may have missed it.)


    Reply
  • dstarr3
    I really wonder what a consumer could possibly want this for. What is an ordinary consumer doing that they absolutely cannot risk any downtime whatsoever on their rig?
    Reply
  • nzalog
    I know freenas can be configured to work faster if you can for sure trust the system from not having RAM errors (covered by ECC) and if you can guarantee there is no unexpected shutdown (covered by dual power and ups). However the reliable power is not really required because a SSD as an SLOG device will cover for it, but then the SSD becomes the bottleneck for writes.
    Reply
  • firefoxx04
    I build several file servers a month for clients. Low end enough to where pre built solutions are not an option. This power supply would be a good fit but it is useless, imo, without some sort of email alert option. Maybe I missed that?

    When I deploy file servers for clients, I always setup some sort of alert system for raid failures so I can fix the problem. What is the point of redundancy if the user has no idea a problem has occurred? Yes i know that this PSU makes a "loud buzzer noise" but I cant have that either. The user needs to continue to use the system and they cannot if it is screaming 100% of the time.

    Send me an email alert. Its easy to implement.
    Reply
  • Rookie_MIB
    One thing I'm curious about - what if one unit does fail? Are they bog-standard replacement parts where you can go and buy a similar hot swap redundant power supply or is the system proprietary. If it's the latter, then I don't see many people lining up for this one...
    Reply
  • apache_lives
    A PSU is but one part of a "reliable" machine, to me this will not increase up time or do anything of any value, seems more like a "makes me feel better" part.
    Reply
  • Aris_Mp
    about the first comment, the PSU is certified for up to 50C ambient full power delivery, but I choose to test up to 45C every PSU that passed from my test bench (since I also have to evaluate 40C rated units and I need to keep the same conditions for all).
    Reply
  • PsiReaper
    A perfect PSU upgrade for my UnRAID box..
    Reply
  • shrapnel_indie
    19144735 said:
    about the first comment, the PSU is certified for up to 50C ambient full power delivery, but I choose to test up to 45C every PSU that passed from my test bench (since I also have to evaluate 40C rated units and I need to keep the same conditions for all).

    While I'm glad for that, It's also nice to know if a unit rated at 50°C operation will deliver on its "promise" though. (If you exceed the "promised" rating, like the 40°C rated units @ 45, well, it delivered on its promise and then some.)

    Reply
  • Pompompaihn
    Newegg has several server chassis for sale that come WITH redundant 500w+ PSUs for less money than just this power supply. Given that the market is low end commercial/prosumer, and it's not going to be for gaming or HTPC, why wouldn't you just buy the whole thing for cheaper?
    Reply