Hot Test Results

The following tables showcase the power quality figures of the SeaSonic Focus Plus Gold 750FX, which generally are very good. The maximum voltage ripple on the 12V line is 30 mV, which is admittedly an unimpressive figure when compared to higher tier modern products, yet it's undoubtfully excellent for a mid-tier product as it's merely 25% of the ATX design guide's recommended 120 mV limit. The filtration of the 3.3V and 5V lines is equally good, with our instruments reading a maximum voltage ripple of 16 mV on the 5V line. Voltage regulation is at about 1% for all three voltage lines, an excellent figure for a product of this class.

Main Output
Load (Watts) 151,22 W 377,29 W 562,75 W 746,85 W
Load (Percent) 20,16% 50,31% 75,03% 99,58%
  Amperes Volts Amperes Volts Amperes Volts Amperes Volts
3.3 V 1,81 3,36 4,53 3,36 6,8 3,33 9,07 3,32
5 V 1,81 5,04 4,53 5,03 6,8 5,01 9,07 5
12 V 11,25 12,09 28,11 12,07 42,17 12 56,23 11,94

 

Line Regulation
(20% to 100% load)
Voltage Ripple (mV)
20% Load 50% Load 75% Load 100% Load CL1
12V
CL2
3.3V + 5V
3.3V 1% 10 12 12 14 10 14
5V 0,9% 12 12 16 16 14 14
12V 1,2% 14 18 26 30 32 16

The energy conversion efficiency of the SeaSonic Focus Plus Gold 750FX barely even drops when the unit is operating inside our hotbox, indicating excellent resistance to thermal stress. The degradation increases when the load is greater than 600 Watts, suggesting that the components of the PSU are facing some thermal stress, as expected under such high ambient temperatures after reviewing the specifications of the unit. The average efficiency reduction is only 0.5%, with the worst figures being 0.8-0.9% when the load is greater than 600 Watts.

Unlike before, the cooling fan of the SeaSonic Focus Plus Gold 750FX PSU started immediately after we powered on the PSU into our hotbox. Even at the lowest of loads, the fan is now both spinning and audible, with its speed increasing as the load increases. The speed of the fan peaks when the load reaches 600 Watts, maintaining barely operational temperatures under such adverse operating conditions.

Cold Test Results (Room Ambient Temperature) Final Words & Conclusion
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  • Dragonstongue - Thursday, May 16, 2019 - link

    I myself have the Seasonic G650 (SSR-650RM)
    I LOVE IT
    is whisper quiet and rock stable. I have not really loaded to the hilts, however main review places including JohnnyGuru listed as very solid including above its rating (without getting uber overheat in the process)

    The other reason I like this vs many of the new Focus ones (plus, gold etc) it has 2 CPU power connectors (1 4+4 on main leads with 20+4 mainboard etc) and if need, can add additional 4+4 for the more power hungry or w/e kit that requires a 2nd eps connector.

    many of the new ones do not get this 2nd connector till the 900w range (pretty sure the 850s not have, at least when I went through them they did not, more of everything, but that connector, granted most boards work off 4+4 just fine including overclock, but there are some boards that "require" for various reasons that 2nd connector.

    EVGA makes some "modeled" after these from their GQ and so forth lines (just as good in most cases, have to back check the model number takes but a few moments .. I believe for EVGA would be G2 P2 and up type deal, I forget ut one of their lines was def more "budget" I think was the "Q" in model number (I could be very wrong)

    Anywho, thank you for the review, they really do solid PSU Seasonic does, that is why they are #1 for consumer grade PSU applications.
  • DanNeely - Thursday, May 16, 2019 - link

    Newegg lists 7 dual EPS models in the 600-650W class. Nothing smaller though; hopefully they'll continue to trickle down 500W would be enough for a lot of non-GPU centric HEDT systems.

    It's a real shame that the way the EPS and PCIe 12v standards evolved that we've got 2 mutually incompatible 8 pin 12V connectors. It'd've made things so much simpler going forward.

    https://www.newegg.com/Product/ProductList.aspx?Su...
  • Death666Angel - Thursday, May 16, 2019 - link

    Since it's really just GND and +12V, all you need is an adapter cable. Or if you want it tidy, just buy an EPS plug and switch the pins from a PCIe plug (and loop a GND and +12V). Anything modular you can also just see how the layout is and get another EPS cable, often they are identical at the PSU side to the PCIe cables.
  • schujj07 - Thursday, May 16, 2019 - link

    I have built several PCs with the Seasonic Focus Gold, semi-modular version of the Focus line and without the semi silent piece, and they are awesome. The Focus/Focus Plus line is my go to recommendation for people who are looking to build a PC or upgrade their PSU.
  • GeoffreyA - Thursday, May 16, 2019 - link

    Greetings, sir, and thank you for this review. If I may, I'd like to ask a question concerning the semi-modular, non-plus, Focus Gold units (specifically the 450W and 550W models: the SSR-450FM and SSR-550FM). I wonder, will they be more or less the same quality as the Plus versions, and are they recommended? Online, reputable reviews of these units are sorely lacking.

    Much thanks and have a good day.
  • vidal6x6 - Thursday, May 16, 2019 - link

    I have Here a old 800w 11 years and It is rock and solid performance. now without cooler :)
    Dead silence! Running 2 xeon L5630 and a 660TI
  • KAlmquist - Saturday, May 18, 2019 - link

    In general it's hard to judge the quality of lower power units based on reviews of units with higher power rating. I believe that lower power units are (1) likely to face more intense price competition and (2) are less likely to be looked at by reviewers. So there is an incentive for manufacturers to cut corners on the lower power units.

    I also note that the unit reviewed here is from the FX line, whereas the units you are asking about are from the FM line. The FX line has a 10 year warranty. The FM units come with a shorter, although still respectable, 7 year warranty.

    That said, Seasonic has built up a reputation over a long period of time, and I'd confident buying Seasonic based on brand alone. If we were talking about any other manufacturer, I'd say you shouldn't buy a power supply without seeing a review, but I make an exception for Seasonic power supplies.
  • GeoffreyA - Saturday, May 18, 2019 - link

    Thank you for your response, KAlmquist. I do appreciate it, and completely agree with you. Seasonic certainly has a reputation for quality.

    I am going down a fairly budget path and will be buying the 450W FM unit this July (or one of these months). I'm just waiting for AMD to release Ryzen 3000. The Ryzen 3 3200G, if there turns out to be such a CPU, is likely what I will get (even though it won't actually be Zen 2).

    Thanks again and take care.
  • Death666Angel - Saturday, May 18, 2019 - link

    As long as you stay in the respective line up (e.g. 750W Gold FX Edition reviewed vs 450W Gold FX Edition bought) it is usually pretty similar to identical. If you buy a PSU from a manufacturer because another series higher power (higher cost) PSU did well in a review, you might get a bit of a surprise. However, if you stay with certain brands / OEMs, you are fine. I inherently trust anything Seasonic, Silverstone, Corsair with 80+ bronze. Something like Cougar, Cooler Master, NZXT, Super Flower, XFX, Sharkoon , Thermaltake can be fine or great even. They also sometimes have good sales. But they can also have duds. Although not as much as back in the day. There used to be a saying in German "don't buy a 'Chinaböller' [chinese fireworks]" when talking about these low tier brands. It's not that bad anymore. But I'd still get a used decent brand PSU than a new questionable one without reviews. I think Cougar once had a "scandal" where their 80+ certificate was achieved by another design that was not actually sold. Those things happen increasingly rarely (what doesn't sound right) and are eventually exposed and you might get some of your money back because of false advertising. But mostly 80+ certification is pretty good, consistent and reliable.
  • GeoffreyA - Sunday, May 19, 2019 - link

    Thank you for the advice, Death. And you're quite right. I learned years ago what a no-name PSU can do to a computer. Back then, my old Athlon 64 survived but was never quite the same again. I replaced it with a somewhat better one: an AOpen unit seemingly made by FSP, but the damage had already been done.

    I will get the SSR-450FM unit (or the 550 one if I can afford it). Indeed, they are from the value line but do carry a 7-year warranty (and are 80+ gold). The funny part is, in my country, South Africa, Seasonic units are impossible to find, yet lesser units are doing the rounds. At any rate, I'll buy the Seasonic from Amazon.

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