Seasonic Focus Plus 750 Gold PSU Review

Seasonic's Prime Titanium, Platinum, and Gold families are already available, and the company still isn't done: we're now looking at its Focus series, consisting of the Focus Plus and vanilla Focus. The aforementioned Prime models are mostly aimed at enthusiasts, while the Focus units target value-oriented buyers. According to Seasonic, its Focus Plus and Focus PSUs will eventually replace the popular G and S12G designs.

With the release of its Focus models, Seasonic is implementing a new policy that should make evaluating its products more transparent. From now on, reviewers will only receive Seasonic samples from online vendors, rather than the factory. While we do see ways this system could be gamed, implemented properly, it's a big step forward in ensuring reviewed hardware is representative of what readers will find on store shelves.

Why didn't anyone think of this sooner? The fact is that most companies want to check the samples sent to reviewers first. Some manufacturers go a step further and only ship off their best-performing products, which then come to be known as golden samples. Of course, we understand the desire to make a good impression, but this practice becomes problematic if retail hardware is found to have issues not seen in reviews.

The Focus Plus Gold line consists of four members with capacities ranging from 550W to 850W. They're all 80 PLUS Gold-rated, certified by Cybenetics for ETA-B-class efficiency, and equipped with fully modular cabling. The model we're testing today is the SSR-750FX, Seasonic's 750W implementation. It's a mid-capacity PSU suitable for use in a capable gaming system with a couple of high-end graphics cards and an overclocked CPU.

Specifications

Seasonic arms the SSR-750FX with a full complement of protection features, and it rates the unit for continuous full load delivery at temperatures as warm as 50°C.

Unfortunately, the 120mm cooling fan is a little small; this plays a major role in the noisy operation under taxing loads and high ambient temperatures that we measured. Then again, the chassis' compact dimensions limit Seasonic's options. A 135mm or 140mm fan simply wouldn't have fit. According to Seasonic, it uses a fluid dynamic bearing-based fan, so it should last a long time. The fan is supported by a semi-passive mode.

Of course, we're big proponents of long warranty periods, so long as they're realistic. Seasonic's 10-year coverage is a result of the company following its competition, even in this mid-range category.

Finally, the dimensions of all Focus Plus Gold PSUs are very compact, given a mere 14cm depth. To the best of our knowledge, only SilverStone's ST85F-PT matches Seasonic's power density score.

Power Specifications

Rail3.3V5V12V5VSB-12V
Max. PowerAmps20206230.3
Watts100744153.6
Total Max. Power (W)750

Maximum combined power on the minor rails is limited to 100W, while the +12V rail can deliver up to 62A of current. The 5VSB rail has a 15W capacity, so it is a little stronger than what we'd expect.

Cables And Connectors

Modular Cables
DescriptionCable CountConnector Count (Total)Gauge
ATX connector 20+4 pin (610mm)1118-22AWG
4+4 pin EPS12V (655mm)2218AWG
6+2 pin PCIe (680mm+80mm) 2418AWG
SATA (455mm+115mm+115mm+115mm)2818AWG
Four-pin Molex (460mm+125mm+125mm)1318AWG
FDD Adapter (+110mm)1122AWG

There are two EPS and four PCIe connectors, so this PSU easily supports a high-end motherboard and a couple of enthusiast-oriented graphics cards.

All of the cables are long enough; however, the distance between peripheral connectors should ideally be 15cm.

Power Distribution

Since this PSU features a single +12V rail, we do not have anything to say about its power distribution.

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  • none77
    Thank you for the detailed review.
    In the transient response test
    Advanced Transient Response at 50 Percent – 200ms
    the +3.3 pass.
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  • BugariaM
    As always, here are the most detailed reviews on the PSU.
    Thank you and keep it up!

    The only thing that is not quite clear to me. What is the criterion for voltage drop in % to get PASS/FAIL in "Advanced Transient Response Tests"?

    You declare that:

    "In all tests, we measure the voltage drops." The voltages should remain within the ATX specification's regulation limits. "

    For ATX 2.2 we have:

    12v - 10%
    5v - 5%
    3.3v - 5%
    5VSB - 5%


    However, looking at your reviews, there are often situations where, at <5%, the power supply gets the FAIL mark and vice versa, some at >5% receive PASS

    Why is this happening?
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  • BugariaM
    Sorry, a typo
    Of course for 12v - 5%
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  • Aris_Mp
    the limit is 5% however the voltage rails of the PSUs' under test in the majority of cases aren't at the nominal voltages, but higher, so even with 5% deviation voltages go don't bellow the limits that the ATX spec sets (11.4V, 4.75V, 3.14V). Only if a rail goes below those voltage levels it fails. The 5% is just an indication that the ATX provides to specify the voltages above.
    1
  • BugariaM
    Now everything became clear to me.
    Thank you.
    1
  • fredlaso
    Dell Inspiron 5675 Desktop, PSU (power supply unit), upgrade. Would this PSU compatible with Dell Inspiron 5675 Desktop. It came with 460W I would like to replace it with PSU between 650 to 750W. I tried at Dell forums but cannot get a clean link which one would be compatible.

    I would greatly appreciate if someone could help me out. Thank you kindly in advance:

    http://en.community.dell.com/support-forums/desktop/f/3514/t/20019321?pi21953=1#21018407
    http://en.community.dell.com/support-forums/desktop/f/3514/p/20024419/21031446#21031446

    System Comp,:
    Compatible Power Supply needed for Inspiron 5675 Gaming Power Supply
    Specs:

    AMD Ryzen 7 1700X 3.4GHz Octa-Core Processor
    8GB 2400MHz DDR4 RAM
    1TB 7200 RPM Hard Drive
    AMD Radeon RX 580 8GB GDDR5 Graphics Card
    DVD+RW Drive
    Dual Band WiFi 802.11ac + Bluetooth 4.1
    Windows 10 Home (64-bit)
    460 Watt Power Supply w/ Polar Blue LED
    Includes: Dell KB216 Wired Keyboard + Dell MS116 Wired Mouse
    Ports:
    6x USB 3.0
    1x USB 3.1 Type-C Gen 1
    2x USB 2.0
    1x Audio Combo Jack
    1x 3-in-1 Media Card Reader
    1x P/S 2
    1x 7.1 Channel Audio Out
    Expansion Slots:
    3x 3.5" bay
    2x 2.5" bay
    2x PCIe x1
    2x PCIe x16

    http://en.community.dell.com/support-forums/desktop/f/3514/t/20019321?pi21953=1#21018407
    http://en.community.dell.com/support-forums/desktop/f/3514/p/20024419/21031446#21031446
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