The Seasonic Focus Plus Gold 750FX 750W PSU Review: SeaSonic Quality at Mainstream Prices
by E. Fylladitakis on May 16, 2019 10:00 AM EST- Posted in
- Cases/Cooling/PSUs
- Seasonic
- PSUs
- 80Plus Gold
- 750W
External Appearance
Despite its relatively high power output, SeaSonic managed to fit the Focus Plus Gold 750FX into a standard ATX 150 × 140 × 86 mm (W×D×H) chassis. The 140 mm deep body ensures that the Focus Plus Gold 750FX will fit in any ATX-compliant case, including Desktop HTPC and other compact designs. The sticker with the electrical specifications and certifications of the PSU can be found at the top side of the unit.
Although SeaSonic usually is very subtle when it comes to aesthetics, we can safely declare that the Focus Plus Gold 750FX is an exception. The designer clearly went out of their way to make this PSU aesthetically appealing beyond just a good paint job. At the bottom of the chassis, we find a unique fan grill with a golden badge at its center and grey accents surrounding the fan. Embossed geometric designs can be found on the left and right sides of the PSU, while the gold-accented company and series logos can be found on every side.
Besides the typical on/off switch and an AC cable receptacle, SeaSonic also placed a square locking switch on the rear side of the PSU. This switch can be used to enable the cooling fan’s hybrid control mode. Enabled by default, in hybrid mode the fan will turn on only when the unit’s load is high enough to require active cooling. Otherwise if hybrid mode is disabled, the fan’s speed will still be thermally controlled, but it will always run and never go completely fanless.
Meanwhile the front of the PSU is home to the connectors for the modular cables. SeaSonic did not color-code the connectors, but they have a basic legend printed on the chassis that indicates where each connector goes. PCI Express and CPU 12V cables share the same connectors. It is practically impossible for a user to insert a cable into the wrong connector, as each cable type has a different connector and the connectors are keyed.
Internal Design
The cooling fan under the fancy finger guard is the HA1225H12F-Z from Hong Hua. It appears visually simple but features a high-quality Fluid Dynamic Bearing (FDB) with a high life expectancy and promises relatively low noise levels. It has a theoretical rotational speed of 2200 RPM but is thermally controlled and should only actually reach those speeds if the PSU is highly stressed.
There is no need to verify the OEM of this unit as SeaSonic obviously is both the designer and the maker of this power supply. The interior of the unit is very tidy, shouting the obvious lack of wires between the main and the connector’s PCBs, which are joined together via a large copper bridge. The heatsinks are worryingly simple for a PSU of this power rating, suggesting that SeaSonic is very confident regarding its conversion efficiency.
A small PCB is soldered on the back of the AC cable receptacle, hosting a few parts of the filtering stage. The total filtering stage consists of four Y capacitors, two X capacitors, and two filtering inductors. A MOV is also present, as well as an IC that handles the discharging of the filtering capacitors (CM02X). Right after the filtering stage, two bridge rectifiers share the one and only high-density heatsink found in the unit.
The APFC circuit is textbook, with the active components on the thick, crude heatsink across the edge of the PCB. Nippon Chemi-Con supplies the single 400V/560μF capacitor that sits next to a decently-sized enclosed-type filtering coil.
A rare sight these days, the Focus Plus Gold 750FX sports four primary inversion side MOSFETs that form an LLC resonant full-bridge topology. On the other side, another four MOSFETs generate the single 12V line. The DC-to-DC converters for the 5V and 3.3V voltage lines can be seen on the moderately sized vertical PCB that has a heatsink hidden behind it. All of the secondary side capacitors, electrolytic and solid alike, are made by Nippon Chemi-Con.
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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.