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FSP Hydro X 450 Power Supply Review

After the Hydro G series, FSP decided to release a more affordable power supply called the Hydro X, which targets systems with lower energy needs. This PSU line consists of three units, and in this review we're testing the entry-level 450W model.

Transient Response Tests

Advanced Transient Response Tests

For details on our transient response testing, please click here.

In these tests, we monitor the response of the PSU in two different scenarios. First, a transient load (10A at +12V, 5A at 5V, 5A at 3.3V and 0.5A at 5VSB) is applied for 200ms while the PSU works at 20 percent load. In the second scenario, the PSU is hit by the same transient load while operating at 50 percent load. In both tests, we use our oscilloscope to measure the voltage drops caused by the transient load. The voltages should remain within the ATX specification's regulation limits.

These tests are crucial because they simulate the transient loads a PSU is likely to handle (such as booting a RAID array or an instant 100 percent load of CPU/GPUs). We call them "Advanced Transient Response Tests," and they are designed to be very tough to master, especially for PSUs with less than 500W capacity.

Advanced Transient Response at 20 Percent

VoltageBeforeAfterChangePass/Fail
12V12.028V11.787V2.00%Pass
5V5.017V4.859V3.15%Pass
3.3V3.354V3.171V5.46%Pass
5VSB5.050V5.003V0.93%Pass

Advanced Transient Response at 50 Percent

VoltageBeforeAfterChangePass/Fail
12V11.970V11.753V1.81%Pass
5V4.969V4.799V3.42%Pass
3.3V3.318V3.105V6.42%Fail
5VSB5.000V4.942V1.16%Pass

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The +12V rail's response to transient loads is average; the same applies to the 5V rail. On the contrary, deviations at 5VSB are much lower. Finally, our usual suspect, 3.3V, registers the worst performance. In both tests, the 3.3V rail reports very high deviations. In the second one, it even fails to keep its voltage within the ATX spec's range. It's been a while since we saw a PSU fail here.

Here are the oscilloscope screenshots we took during Advanced Transient Response Testing:

Transient Response At 20 Percent Load

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Transient Response At 50 Percent Load

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Turn-On Transient Tests

In the next set of tests, we measure the PSU's response in simpler transient load scenarios—during its power-on phase.

For the first measurement, we turn off the PSU, dial in the maximum current the 5VSB can output and switch on the PSU. In the second test, we dial the maximum load the +12V can handle and start the PSU while it's in standby mode. In the last test, while the PSU is completely switched off (we cut off the power or switch off the PSU by flipping its on/off switch), we dial the maximum load the +12V rail can handle before switching on the PSU from the loader and restoring power. The ATX specification states that recorded spikes on all rails should not exceed 10 percent of their nominal values (+10 percent for 12V is 13.2V, and 5.5V for 5V).

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There are no spikes or voltage overshoots here, except a tiny one in the last test. Everything is fine. 

  • powernod
    Do Hydro PSUs work underwater?


    Yeah, they have to work underwater in order to camouflage themselves from Corsair's (PSUs) who dominate the water's surface!! :p
    Or to pass through the Seasonic wall !!:lol:

    ONTOPIC: Decent PSU from FSP, but only just decent!!
    Reply
  • Aris_Mp
    it is hard to enter the US markets with Corsair and EVGA throwing one model after the other and in very competitive prices, however more variation is always welcome. If they lower significantly the price tags on these models then their marketing career will be easier.

    Reply
  • Dark Lord of Tech
    Hard to penetrate the EVGA lineups with their great prices on the higher end units. These need to be lowered to sell.
    Reply
  • turkey3_scratch
    Is there any reason the 3.3V rail shows strange behavior when crossloading? Not that it's bad or anything, but in CL1 with heavy load on the 3.3V rail, the voltage is about 0.10V higher than CL2, where the 3.3V rail has minimal load, and voltage is typically higher.
    Reply
  • turkey3_scratch
    Okay, just finished reading the review. Besides the disappointing transient response of this unit, and the failure to meet hold-up time, this is a good unit. But the price needs to drop to about $60 IMO if it wants to compete well. Currently it's priced the same as the Hydro G 650W, and the Hydro G is a no-brainer choice over this unit.

    It also concerns me a bit that the 5V rail voltage goes to 4.79V in your second transient response test at 50% load. This is all around also a bit disappointing, but it's not a very realistic transient load (unlike 12V which happens always while gaming), but I like the Japanese capacitors, the load regulation is fine, the crossload graphs all show good results; sometimes a lot of units screw up on those. It's nice to be able to see those different load patterns, something other reviewers should try to adopt. Ripple was very nice.
    Reply
  • joz
    Hard to penetrate the EVGA lineups with their great prices on the higher end units. These need to be lowered to sell.

    G2 is love, G2 is life. (G2 550W, about...eight of them....)
    Reply
  • basroil
    FSP almost had an excellent PSU until they screwed up big time on the transient response. Looks like the EVGA G2/ SuperFlower Leadex Gold is still king of the inexpensive PSUs
    Reply
  • Flying-Q
    Please stop referring to quality PSUs with low wattage as 'entry 'level' (in the article subtitle).

    Entry Level (adjective)
    (of a product) suitable for a beginner or first-time user; basic.
    "entry-level computers"

    'Entry level' usually implies smaller feature set. In this instance the feature set of each of the models is the same other than the power output. Current generation computers need less power due to greater efficiency inherent in more recent designs of components.
    Reply
  • turkey3_scratch
    17768395 said:
    FSP almost had an excellent PSU until they screwed up big time on the transient response. Looks like the EVGA G2/ SuperFlower Leadex Gold is still king of the inexpensive PSUs

    I would like other testing sites to start adopting these tests, like Jonnyguru. I wonder how many units that normally pass stuff would fail.

    Another funny thing is FSP just wrote a blog about the importance of transient response. :P

    But also, a 3.3V transient response just doesn't happen in 2016, probably never will. A 5V one is also less common.
    Reply
  • basroil
    17769266 said:
    But also, a 3.3V transient response just doesn't happen in 2016, probably never will. A 5V one is also less common.

    ATX loading specs state a 9A transient on 12V (and 5V might have been there). Considering most modern PSUs are 12V only and then DC-DC for 3.3 and 5V, 12V transients are going to end up affecting the 5v and 3.3V lines too.
    Reply