Seasonic Focus GX-750 V4 ATX v3.1 PSU Review

18 thoughts on “Seasonic Focus GX-750 V4 ATX v3.1 PSU Review”

1. Very good review. Also excellent input from the comment section. I’d like to add a personal experience with Seasonic. To me it seems like they have systemic problems at Seasonic regarding the protection circuit. I got a AM4 Gigabyte ITX board with a Ryzen 5700G for very cheap from a seller who pics his parts on pure marketing sentiment. The system had issues with the graphics from the start. But as soon as I added a 6600 XT DGPU it became unstable. Upgrading the graphics drivers (IGPU and DGPU) made the system crash hard while idling at for a long time. By crashing hard I mean that I had to disassemble the DGPU and rewire it to a different outlet of the PSU (SEASONIC FOCUS GOLD FX550) before it would restart. I assumed a broken soldering point in the PSU had caused the crash at that time) An OS image (containing the old GPU drivers) was put back and everything seemed fine until I decided to update the GPU drivers again. After the driver update the PSU began to shut down the system randomly. Strangely enough the shut downs happened not while the DGPU was on full load but as soon as the NVME drive was writing large amounts of data. Soon the system PSU protection was also triggered while the system was idle. It even crashed while configuring the bios. I expected an almost dead mosfet on the main-board or the PSU was dying. I ordered a new PSU after searching for problems with this Seasonic PSU. All the problems vanished after building the new PSU in.

   I did found problems with FX Gold line from Seasonic.
   Seasonic claimed that the protection of the Focus Gold FX550 could only be triggered with high transient spikes. That was NOT my experience as the 6600 XT does not produce these kind of spikes. Their solution was crappy to say the least. Seasonic provided different cables for problematic GPU’s like extra shielded cables and/or cables with capacitors build in. To me that was the red flag. Providing 10 years of warranty says nothing but addressing a big problem in the protection circuit with “magic” new cables says it all; Seasonic does not adress their design faults. They should have recalled the Focus Gold FFX line but they did not potentially causing damage to the costumers. After repair I decided to open up the PSU. I did not care about the warranty because it’s useless if you get a repaired PSU back with the same faulty design. I noticed two things in this five years old PSU that never had to work up to specs. First I noticed that the placement of a row of the high powered transistors was far from ideal. Seasonic had placed it against one side of the enclosure. I think that was on purpose because a NTC had been placed against one of the transistors. The NTC is there to limit the inrush current. This NTC looked absolutely backed I suspected it was failing. The PCB under it also looked backed both had been discolored like a more brownish color instead of blue and green one. In my old PC I have a more then 10 years old, much cheaper, Antec PSU of the same wattage. I cleaned it out two years ago and everything inside still looks fresh while the system draws a lot more power because the outdated Phenom II it feeds needs a lot of power. The Antec PSU is also heavier because it’s populated with more parts. What I especially dislike about Seasonic is their simplistic consumer base who fall for Seasonic’s marketing (we are the best bla bla) Seasonic is nothing special no matter how Japanese the capacitors they use are. And now again years later problems with the protection circuits of another line of Seasonic PSU’s. I prefer the highest tier Mars gaming PSU, over a Seasonic mid tier PSU they are that bad. Their marketing strategy makes me suspect that reviewers falsely praise Seasonic PSU’s. That’s pure speculation but it is very hard to find an honest review like this one on HWBUSTERS. Therefore I bookmarked hwbusters site and took the time for writing down my detailed experence in this comment section. Oh, the new PSU I bought is a “mid tier” Corsair RM750E with a lot of Korean capacitors in it. For those brand following idiots; They do how to make good capacitors outside of Japan also.

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2. Hello.
   I see that inrush current is almost 200A at 230V… is that real? Would this much power trip circuit breakers in the house or damage anything?
   Is this PSU safe to use? I have it but now im scared to turn it on…

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   1. it is real yes. It is for a very short period, so it doesn’t trip the breaker.

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      1. Thank you for your fast response.
         Does this high inrush current do anything to the lifespan of the PSU or PC?
         I usually power off the PSU at night and power on in the morning to avoid the bright LED lights in my room and now im worried.
         I wish i read your review on this PSU before i bought it. Im very disappointed in Seasonic.

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         1. It is hard to drain the APFC bulk caps completely. We follow a special procedure to do so. But yeah, they could use a larger NTC thermistor to lower it because we also have Murphy’s laws.

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         2. The worried kind of type of PC users are of special interest to me. They somehow sense their hardware is being degraded, just by using it, especially by gaming, but they don’t seem to know how and why that happens. It happens because hardware overclocking has been standardized. Smart algorithms like XMP rape the memory rows silently one by one by overvolting while the CPU is being trashed by algorithms like precision boost overdrive or the Intel equivalent. Still they activate it all just for those extra frames and 5% faster CPU performance. And of course those features put a lot of strain on the PSU because the power demand is fluctuating much more then in a system configured to perform conform hardware specs like a server or workstation. Meanwhile the hardware producers have a blast. The dumb consumers replace broken parts endlessly while their systems are being used as a test platform (yes those drivers send feedback to Intel, AMD and the likes everything a blue screen occurs) Stop worrying because your system has been produced and pre-configured to die prematurely while leaving the user in the dark about the reasons why. The newest trend is undervolting (as if IC’s don’t need to have operating specs) And now the PSU manufacturers have joined in on the fun by starting producing PSU’s that will only start to cool themselves (a bit) when the transistors inside reach the absolute maximum temp in which they manage to operate. At least the system fries and dies silently because that’s what consumer/gamer wants. Meanwhile they think their favorite hardware manufacturer can’t do wrong while they are being…..and their wallet is being emptied.

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      2. Excellent content. Have you had the chance to try the Seasonic CORE V2 GX-850 (ATX3) – 850W? I’m thinking about buying it, but I’m having doubts. I only found a video on YouTube.

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3. Hi
   Thanks for the valuable work, there was an older ATX 3.0 version:
   https://seasonic.com/atx3-focus-gx/
   From other reviews seems this V3 version is the most reliable one, dodn’t you review that by chance? Best.

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   1. I have the V3 in one of my systems, it’s a solid psu. Aris might not have reviewed it but Anandtech did

      https://www.anandtech.com/show/21101/the-seasonic-focus-gx-850-atx-3-0-psu-review-cool-quiet-and-robust

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4. Hi
   What about SeaSonic Focus GX-750 ATX2 version?
   Does it also have those issues mentioned in the cons section?
   And those listed as cons can be damaging the other parts of the system?
   Thanks

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   1. I don’t have a clue what they fixed and what not, sorry. Seasonic barely sends me any samples to review.

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5. Thank you for the review. You have helped me find good series of Kolink PSUs which have been proving good for the price. Fractal seems to be a very good alternative to Corsair, for similar prices.

   I have been keeping away from Seasonic units due to lack of protection features.

   I had both S12-IIs and M12-IIs (two units each) that only had a simple form of SCP protection. If there is any resistance in the path (as in a broken MOSFET), it will keep draining until one of this happens:

   – Something blows up due to melting/burning shorted component.
   – The PSU shuts down due to undervoltage protections (which from reviews of this platform seem to be set way too low).

   Despite this, Seasonic claims that all protections work despite multiple of evidence from reviews that this platform was broken.
   This was 10y ago and it has cost me hardware that was plugged into the damaged parts (which I didn’t knew had failed). A shame because otherwise they are very reliable, mostly silent PSUs.

   You especially cannot run Seasonic PSUs unattended, as many models have proven to be a fire hazard due to non-functioning ATX protections like described in this review. Stay away!

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   1. Forgot to add that I had a 3rd Seasonic made XFX Core PSU that had the same issues. So, that is quite the track record of not doing QC properly.

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6. Any news about the 750w protection features?

   I think you were right and a lot of people who read your review are wondering if the retail 750w model should be considered when making a purchase.

   Thanks a lot for all the amazing work.

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   1. Still, no new fixed sample from Seasonic.

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7. Would you consider testing the Super Flower Zillion FG ATX3.1/PCIe 5.0 power supplies? I’ve recently stumbled across them as they are currently on sale and was wondering if they were good.

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   1. I will review them in the future!

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8. Aris you should review the SuperFlower Leadex III ATX3.0

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