Seasonic X-850(SS-850KM3 Active PFC F3) 850W 80 Plus Gold ATX12V/EPS12V Power Supply

Still going strong after 8 years. Has powered two builds so far (R7 1700 + GTX 1070 to R7 9700X + RTX 5060 Ti). It's pretty quiet and is pretty much the one of the few parts that survived my PC upgrade.

Seasonic is well known to make power supplies with high end components such as Nippon Chemicon, capacitors from Japan, durable Sanyo San Ace dual ball-bearing fan, excellent input filtering, regulation, and overall premium build quality. Currently for the last 15 years Seasonic has been my primary brand of power supplies I would use for my builds as well as my friends and family. With the crazy weather we've experienced the last few months, it's not uncommon for us to experience brown outs or intermittent black outs. Even after all of the electrical problems in my neighborhood my 2 machines running both the Seasonic X-850 and Seasonic Platinum 760 are still holding up quite nicely. Since my Platinum replaced a competitor's product (one with a sail) that failed last summer, I've been migrating all of my equipment to UPSs for battery backup and additional protection. That said, owning a UPS does NOT guarantee reliable operation of a power supply. Case and point, last night a longtime good friend of mine called up from out of state for assistance troubleshooting his PC that refused to power back on after a power outage. He had his machine connected to a battery backup, lost power then proceeded to power off his equipment. After utility power came back on, his PC refused to power on or POST. After some basic troubleshooting, I've had him disconnect the power supply from his components and short the green pin to a black pin on the ATX24 connector to manually power on. No dice, the fan didn't spin. To verify once more, I had him use his multimeter to read the DC rails, Yellow for 12v, Red for 5v, and orange for 3.3v; only the 3.3v rail output anything. It's dead Jim. He also did not use a Seasonic Power supply, instead he opted for one that was on sale at a big box store.The point of the story being, his Non Seasonic power supply was approximately 4 years old when it died past it's warranty, and my dead corsair also lasted a little past it's 3 year warranty. As for Seasonic, since 2002, I've owned a few of their units. None has come to mind that has failed on me yet. I've also given away an old 620W 80plus model I've purchased in 2006 that's still kicking to this day confined in a desk cubby with inadequate air flow.I can babble on for hours about how great this unit is on efficiency, how quiet it is, build quality, rail quality, customer service, etc.But here's what it boils down to:"How reliable is this unit?" Very reliable. "What happens if this fails?" Contact Seasonic, they'll ship you a replacement unit. Also this won't kill motherboards and components like the Bestec power supplies did. (Look that one up guys)"Why buy this when I can buy 100000W brand XYZ power supply for half as much?" When you spend $300+ for a CPU, $400 for a GPU, $150 for a case, you can budget some money in a quality power supply that will easily outlast your video card in terms of functional use. Go ahead, save some money, buy a cheap crap PSU, but don't cry when your expensive part fails.

I'd replaced two thermaltake psu's in the past that just quit. Finally replaced them with a 650w antec (antec are rebranded seasonic) and never had a issue since. So for my new build, I purchased this PSU. Plenty of power for my build:i4770k 16gb - ASUS maximus VI heeroGTX7804x SCSI3 HDD's1x SATA2x opticalThe gold rated efficiency claim I tend to view more as marketing since psu mfg's police themselves, besides, efficiency ratings only matter for over 80% utilization. I don't expect to be taxing the psu that hard all the time (the one 2star review, I don't think 850w is enough for his kit). For me, the quality of the power is what counts. I use a psu tester always before plugging it onto my mb. This unit was solid spot on for all voltages except one plug was 11.9v. Within spec, but there's enough connectors that I can not use that and have plenty to spare. If I add so much hardware I'm actually using all the connections on the psu, I should be buying a bigger psu.It's very quiet. I have mine on normal mode, I don't see a need to go to fanless mode.It's fully modular and comes with a nice sleeved mb power cable, and plenty of black power cords for most anyone. The mb and cpu power cables are long enough to route through a thermaltake A71 full tower with slack to spare connected to a ASUS maximusVI hero full size atx board. Quality of power, ease of installation, and number of connectors are all excellent.A bonus is the bags for the cables that it comes with, and the bag the psu is packaged in. Rather than a rats nest of unused cables, you can keep your spare parts organized, the velvet bag will be stuffed with extra cables in my parts box.The only con would be, for me, is that it is a single rail psu. Single rail psu's mean you don't have to balance the load on the psu, but I'm used to that. Since most psu's now are all single rail, I'll have to grin and bear it.I've been around the block the last 20 years building and supporting machines for a living, electronics fail, fact of life. In my experience though, if it passes burn in, I expect this unit to be as rock solid as any seasonic psu. It's smaller, lighter, made in china, but what isn't nowadays. The one good thing is that seasonics have always been made in china, so I'm pretty confident they know how to make a power supply. Any unexpected failures down the road and I'll update this, but if I need another power supply for another build, I'll be buying a seasonic again.

Bought this brand because they manufacture the Corsair supplies and are a bit cheaper.So far, so good. Tested it with a PS tester prior to install and every voltage was within spec. Not enough standard 4 pin connectors for older legacy devices. I don't have or need 20 SATA device connectors. Gold plated PCIe and mb power, but not the SATA or peripheral connectors. A bit misleading with the advertising. One of the modular PCIe connectors on the supply had a molding defect in the plastic. They can do away with the cheesy felt (or should I say mouse fur) bag and gold plate the 4 pin connectors.Quiet as a church mouse. Cannot hear it with the fan spinning or stationary. No coil wine or other noise. Under load on my system (which runs about 250-300 W in BIOS) my voltage monitors showed 12V bus at 12.120 for four continuous hours. 5V bus was 5.05V, 3.3V bus was 3.260V. All rock solid. That is about 1% tolerance which is fantastic.Pretty happy in general, time will tell if it remains reliable.Update:What a POS. Bought in April of this year and it has failed big time. Cheap Chicom crap.

Sold on Amazon by High Flyer Items. Delivered in the USPS box w/ the outside of the box marked as Seasonic 850W X Series. No Original Box included and No Manual. This appears to be some refurbed or remaindered item sold as new. I previously purchased a Seasonic PSU several years ago and the unit arrived in the Factory Box, with a Manual and a special carry bag for the cables. Awaiting Case delivery for installation and will update rating accordingly.