Anandtech: The Seasonic Focus Plus Gold 750FX 750W PSU Review: SeaSonic Quality at Mainstream Prices

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A review of Mainstream Seasonic PSU:

https://www.anandtech.com/show/14338/the-seasonic-focus-plus-gold-750fx-750w-psu-review

In terms of performance, the Focus Plus Gold 750FX is a great all-rounder, yet a master of none. Its greatest characteristic is the excellent acoustics performance, with the PSU operating inaudibly under low-to-regular load when the ambient temperatures are not too high. The power quality of the PSU may be unimpressive when compared to what top-tier PSUs may achieve, yet the figures are undoubtedly admirable for a mainstream product. It does run a little hot considering its power output and electrical efficiency, yet it's not hot enough to cause any issues.

As good as it may perform, there is a catch with the unit’s specifications that we should note – SeaSonic rates the PSU for operation up to 50°C, yet de-rates its power output for temperatures above 40°C. While the Focus Plus Gold 750FX was able to deliver the entirety of its rated power output while operating in our hot box, the platform is only rated for operation up to 40°C, and higher ambient temperatures will severely shorten the unit’s lifetime. Which for most builders shouldn't be a problem, but it could potentially be a concern if you intend to use the PSU in a consistently warm environment without air conditioning.

Overall, SeaSonic is obviously aiming the Focus Plus Gold series at the heart of the advanced PC market, with units that offer ample power output and good performance for the typical gaming/advanced workstation PC while preserving a relatively sensible price tag. The retail price of $110 is reasonable and on par with other high-quality products of comparable performance and quality, making the Focus Plus Gold 750FX an excellent deal for users that want a very reliable, good all-around PSU.

SEASONIC_FOCUS_PLUS_GOLD_750FX_04_678x452.jpg
 
Nice. I haven't bought a cheap PSU for myself or any build in a long time. Seasonic is at the top of my list, and it's about all I'll use in my own PC these days. Their reputation and quality is top notch. I bought my first one because of the high recommendations of [H] and haven't looked back.
 
The FP Gold lines are iffy. They are great if you are running lower loads (say 400-600W on the 850Ws). Anything higher and they start to warm up (as mentioned). Seasonic also cheapened out on their new cabling vs the x series Gold line these replaced.


This being said, I am running a 1KW FP Gold in my sig rig that replaced 2 faulty 850s (they had a problem with current surge with AMD Vegas which would result in the PSU tripping it's OCP and the system hard powering off).

Seasonic tech support was great, and the upgrade made things better from a feel good point of view.
 
I've been using this PSU and the voltage regulation isn't nearly as tight as all the other gold rated PSUs I've used, it's well within ATX allowable tolerances but just a hair outside the tolerance listed in the specs for it.

It seems like a lot of the gold rated PSUs are getting smaller and lighter so it wouldn't surprise me if many of them are getting worse, it almost makes me want to go pick up a couple of old EVGA G2s before they're all gone.
 
I used the 550w version of this in a recent build and it was my first Seasonic power supply. I was impressed with the build quality.
 
I snagged a 1000 watt Focus+ Gold over black friday. It was too good a deal to pass up. It's way overspecced for the build it's meant for and should it make too much noise I'll sell it here cheap.

Edit
Egads that's a weak review.
 
My GF is running the FP Gold 650W version on my old 4690k (mild 4.2GHz OC) with a slim 1050Ti.

Build quality wise, I agree with ccityinstaller, I wasn't impressed with the cables supplied, but everything else has been running just fine with it so far.
 
Do the cables have capacitors in them?


They do not from the factory but there are aftermarket sets (think like cablemods) that do have them.

In fact the OCP issue with VEGA could be negated with aftermarket cables according to SS.

I forgot to mention that I had to pay $30 via PP to "upgrade" from the 850W to the 1kW unit. I got a new unit, not a refurb but I felt given the 2 failed units and the time involved in troubleshooting, SS really should have given me the 1kW unit free with overnight shipping or let me spend $50 to upgrade to a 1kW Prime Titanium.

I have used over 4 dozen SS units in builds, and the FP+ were the ones that have me the most trouble. I had an 850W X series die after 4 years of 24/7 use and thry replaced that with a new looking 860W Platinum x series so I was happy with that result.


The crazy thing is that the 850W Gold X series (it was the last revision they made with that excellent $30 server fan in it)weighs as much as 1.7 FP Gold 850W units.
 
$110?????? I bought a Seasonic 1KW High end power supply for that much back at the end of 2016! (It was on sale, brand new, from Newegg and I am using it in the machine I am typing on right now.)
 
I haven't read a PSU review in a long time. Is this actually a thing for extra power conditioning?

They do it on these smaller power supplies to save space. The problem is, they like to fail or give off an electrical whine. Sometimes as stated above and with a few users here they have problems with graphics cards too.
 
didn't Seasonic have some issues a few months back with some GPU's under heavy load?
 
didn't Seasonic have some issues a few months back with some GPU's under heavy load?

People want to blame Seasonic for that one but the issue is AMD. Vega 56 and 64 have stupid transient spikes and OCP was kicking in. Vega 64 was having transients in excess of 40 Amps. I'm thinking it's due to the designs not having enough caps or big enough caps to smooth that out.
 
People want to blame Seasonic for that one but the issue is AMD. Vega 56 and 64 have stupid transient spikes and OCP was kicking in. Vega 64 was having transients in excess of 40 Amps. I'm thinking it's due to the designs not having enough caps or big enough caps to smooth that out.


You have first hand experience with Vega? How about 7 of them, and the PSU in question? Do you have an EE degree? I can answer yes to all those questions. The design flaw was Seasonic's issue.

Did you forget about the issue the SAME PSU had with an Asus GTX 970? You know, an Nvidia branded card?

It's fine if you are a Seasonic fanboy, hell I was and still mostly am, but I lay the blame where it belongs; at their feet. They gave me a the "upgrade" to the 1kW unit to keep me from pushing back when I debunked every half baked theory they used. Oh 850W isn't enough for 2 Vegas. Well when they are power capped and running at 70% of their rated speed it's enough for double that. I measured the current draw myself with 2 different meters (don't have a 'scope at home anymore since my old hand me down died and I haven't bothered to ship it here from MD to fix it). The cards were drawing within .02A of what the software monitoring was reporting.

I used a friend's Corsair Ax860 Platinum (which is a Seasonic x860P with Corsair's name on the side) with ZERO issues. When I told SS this, they first tried to tell me it was impossible, but when presented with evidence of it working just fine with the x860W-Plat they themselves send me back as an RMA replacement the denial stopped and they did a 180.

It's time for the fanboy stuff to die, or these companies are going to keep pulling this stuff and trying to keep it quiet.
 
i'm using a vega 56 with the 650w varient of this psu, have had absolutely no issues with it.
 
i'm using a vega 56 with the 650w varient of this psu, have had absolutely no issues with it.


The issues were with the higher wattage units and SS claimed to have made a silent revision so only units made before Jan 2018 had the problem.

I had 2 fail, including one that was made in April or May of 2018.
 
Nevermind delete my post not the argument that likely will start.
 
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They do it on these smaller power supplies to save space. The problem is, they like to fail or give off an electrical whine. Sometimes as stated above and with a few users here they have problems with graphics cards too.

No, they don't do it to save space and the caps in the cables don't like to give off an electrical whine.
 
Nevermind delete my post not the argument that likely will start.

I did not mean to come off super agro, so I apologize for that. I just have a TON of experience with the VEGA uarch and have set up well over 100 of them with 7 of my own.

SS used every excuse in the book to try to get me to drop the issue, DESPITE their press release acknowledging the issue(s). Blaming VEGA was the lazy way out. The reference VEGA design, which was every one I worked with, would have never been PCI-E certified of that were the case.


No, they don't do it to save space and the caps in the cables don't like to give off an electrical whine.


I thought I quoted his reply earlier but just realized I didn't and while you need no back up, I was just going to further add they are used to further reduce ripple. Corsair got a bunch of crap a few years back since their SS based Ax designs used caps and it made the super coool sleeved cables have a funny buldge that the Reddit crowd hated and thought it was due to Corsair being "cheap"....
 
I just purchased this Corsair unit a few weeks ago to replace a faulty EVGA 850 B2.
Is it normal for the efficiency to go over 100%? It seems to do that when under a load like opening a program.

corsair-hx750i-107percent-efficiency.jpg
 
I did not mean to come off super agro, so I apologize for that. I just have a TON of experience with the VEGA uarch and have set up well over 100 of them with 7 of my own.

The problem is it's been well documented that Vega 56 and 64 DO have transient problems. You need a scope to see it as other measurements tools are more then likely not fast enough to catch the transient. We are talking sub 10ms


Here is a post of it tripping the RM850i in muti-rail mode https://forums.guru3d.com/threads/vega-64-on-multi-rail-psu.418128/

They got lucky and managed to catch a 47A transient which 47 * 12 = 564 Watts. OCP SHOULD trip in this case since other parts are likely pushing it well beyond rated current for the rail with a lower wattage PSU model.

Here is a screenshot of somebody testing two Vega 56s in crossfire with furmark having a 102a transient. This is not OK by any means. https://d33v4339jhl8k0.cloudfront.n.../5bf675b22c7d3a31944e3e5c/file-Af5QnaoIYo.jpg

Blaming Seasonic here is really short sighted IMO.

Also FWIW Seasonic is only one of the few vendors that sends out retail samples directly from a retailer to people for review to avoid being accused of cherry picking that some others have been accused of doing.
 
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Seasonic is pretty much the eVGA for customer care in my experience.. top-notch.
 
I just purchased this Corsair unit a few weeks ago to replace a faulty EVGA 850 B2.
Is it normal for the efficiency to go over 100%? It seems to do that when under a load like opening a program.

View attachment 162015

it's most likely a bug in the refresh cycle of the application so that the power in and out aren't refreshing at the same intervals so it shows above 100% efficiency.
 
The problem is it's been well documented that Vega 56 and 64 DO have transient problems. You need a scope to see it as other measurements tools are more then likely not fast enough to catch the transient. We are talking sub 10ms


Here is a post of it tripping the RM850i in muti-rail mode https://forums.guru3d.com/threads/vega-64-on-multi-rail-psu.418128/

They got lucky and managed to catch a 47A transient which 47 * 12 = 564 Watts. OCP SHOULD trip in this case since other parts are likely pushing it well beyond rated current for the rail with a lower wattage PSU model.

Here is a screenshot of somebody testing two Vega 56s in crossfire with furmark having a 102a transient. This is not OK by any means. https://d33v4339jhl8k0.cloudfront.n.../5bf675b22c7d3a31944e3e5c/file-Af5QnaoIYo.jpg

Blaming Seasonic here is really short sighted IMO.

Also FWIW Seasonic is only one of the few vendors that sends out retail samples directly from a retailer to people for review to avoid being accused of cherry picking that some others have been accused of doing.


That's interesting, and I will investigate further. As I mentioned, my old scope is beck East and while the current meters I was using are great, they aren't the end all of measuring.


One thing to note is that SS is the ODM of the Corsair RM series unless I an mistaken. I would never use a multi rail PSU with high end GPUs, but that is just my preference. If you balance the load, in theory each rail should have the exact same characteristics. In practice I've seen units that have double or even triple the amount of 12£V ripple.

I know SS makes 90%+ of the quality "name brand" units. My issue was soley with the FP Gold 850W units, anf their attempt to make m forget my own findings by linking me to a random YouTube video about crossfire power useage anr ignoring their own press release with promises to replace faulty units. They claim it was isolated to a certain bstch but that is not true.

Also, why hasn't AMD been called to carpet over this? I'm curious to know and thanks for the links .
 
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I own a Focus Plus Gold 850w here and it's been awesome for the past year and a half now.

CWT built the RM850i it appears https://www.jonnyguru.com/blog/2015/08/24/corsair-rm850i-850w-power-supply/5/

I'm glad yours has run great. Every other SS unit I have ever purchased has been great. I'm not dinging them for the issue so much as the run around and denial/deflect routine they did when I had the EXACT issue they issued a PR about and claimed they would take care of those of us that had issues.

The FP+ line also had Much cheaper looking (and feeling) cables vs the excellent X series they "replaced".

I forgot that Channelwell made the RM series. It was nagging at me this morning while I was waiting for the IV med to kick in for my spine procedure this morning. I just became lucid enough to see letters properly so thanks for fixing my mistake.

I am happy to say that so far I have not seen an issue with the FP+ 1KW unit and my sig setup, although I am using the much higher quality cabling that came with my X series. SS informed me in writing they were pin compatible and gave me permission to use them if I preferred.
 
I'm glad yours has run great. Every other SS unit I have ever purchased has been great. I'm not dinging them for the issue so much as the run around and denial/deflect routine they did when I had the EXACT issue they issued a PR about and claimed they would take care of those of us that had issues.

The FP+ line also had Much cheaper looking (and feeling) cables vs the excellent X series they "replaced".

I forgot that Channelwell made the RM series. It was nagging at me this morning while I was waiting for the IV med to kick in for my spine procedure this morning. I just became lucid enough to see letters properly so thanks for fixing my mistake.

I am happy to say that so far I have not seen an issue with the FP+ 1KW unit and my sig setup, although I am using the much higher quality cabling that came with my X series. SS informed me in writing they were pin compatible and gave me permission to use them if I preferred.

The focus plus did not replace the X series. The Prime units did.
 
The focus plus did not replace the X series. The Prime units did.


The FP+ Gold units were direct replacements for the X series Gold units. This is straight from Seasonic. They are pin compatible cable wise. They slotted the FP+ GoLd units, pre mining craze, into the price bracket of the X series. I know a lot of the news crawlers stated this but you know how that goes.


The Prime units are all Platinum/Titanium rated are they not?

Interestingly, I just saw that SS offers a Prime ULTRA Gold which I have not seen much of, but they do seem to be a premium model which would be a proper replacement of the X series.

As far as SS tech support (I know I know) knows, their line is that the FP+ Gold are the direct replacements for the X series.

Had I known they offered a Prime ULTRA Gold I would have asked for that as a replacement instead of s slightly higher wattage FP+ Gold unit...:(
 
The FP+ Gold units were direct replacements for the X series Gold units. This is straight from Seasonic. They are pin compatible cable wise. They slotted the FP+ GoLd units, pre mining craze, into the price bracket of the X series. I know a lot of the news crawlers stated this but you know how that goes.

Product segment replacement has nothing to do with pin compatibility. The FP Gold units are not X Series replacements.


The Prime units are all Platinum/Titanium rated are they not?

No, they are not. For instance: https://www.hardocp.com/article/2018/02/28/seasonic_prime_750w_gold_power_supply_review/
 
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