Probably the Best PSU Ever!

The Seasonic Platinum 860W is the best current Seasonic product, and very probably the best power supply available at this time. The delivery contents and the number of connectors are at least above average. The internal design, the fan, and the excellent measurements surpass all current solutions from their competition. Clever ideas like the switch for active or semi-passive cooling operation are welcome extras and work without any complications.

Inside Seasonic uses a powerful variation of the well known resonant converter. As usual, the manufacturer implemented the latest silicon carbide diode in the primary circuit and very good MOSFETs. With a mains filter and further components for EMI filtering the PSU is very well equipped. Other manufacturers tried to cut components here in order to improve efficiency, but here Seasonic still includes passive surge protection and inrush current limitation. As expected, Seasonic uses high-quality Japanese capacitors and very good PCB materials. However, even Seasonic is not safe from problems. We saw ferrite beads on two Gate connectors (part of a MOSFET).

Perhaps the PFC control circuit should get a multi-layer design, since some conducting paths are used for different circuits. This might be a source for differential mode interferences and the reason why ferrite beads are necessary. Apparently Seasonic seems to have no problems with the frequency range of their buck converters used for 3.3V and 5V—some engineers bet on HF litz wires on the storage inductors or reduce the frequency with an external circuit. In addition the ESL (Equivalent Series Inductance) of capacitors gets more and more important. Regardless, Seasonic integrated well chosen components and the soldering quality is impressive.

As noted on the previous page, the Platinum 860W showed no significant weaknesses, only the usual strengths of Seasonic. The ripple and noise voltage is never higher than about 30mV at 12V, and the smaller outputs show even lower results. Moreover there is no significant voltage drop at higher loads; all output voltages are very well regulated. Only the chirping of the PFC inductor becomes noticeable if you are close enough; in a closed PC case the noise should not be audible. Right up to higher loads the fan is quiet—or even inaudible below 40% load if the semi-passive mode is activated. Up to 93% efficiency can be achieved with this design and even at 10% load efficiency is still very good. At very low load the regulation effort is usually high—measured against the operating current. This causes high power loss during low load.

Seasonic has no problem with these power losses and even passive components such as filtering coils can't stop Seasonic from reaching and exceeding the 80 Plus Platinum requirements. That might sound strange at first, but FSP for example changed the input differential-mode choke into two single wires with a ferrite core. The lower inductive reactance opens the doors for differential mode interferences. Other manufacturers try to remove important parts such as OCP to reduce power dissipation. The solution from Seasonic is a major advance, which makes the power supply the flagship in its class. A high efficiency should always be compatible with constant quality, which doesn't mean other solutions wouldn't be acceptable as well. FSP tried to make low prices for their Platinum PSUs—an understandable step.

The larger Platimax models (>1000W) from Enermax might have more extras than the Platinum 860W, but Seasonic includes plenty of extras as well and at least matches what you get with the Platimax 750W. The 60 to 65cm motherboard and GPU connectors are extremely long, and the Platinum 860W can support up to four PEG, eleven SATA, and eight HDD connections. In particular, the number of SATA connectors is very satisfying, and the high quality cable sleeving is another reason to buy this product.

The direct competitors include the already mentioned Enermax Platimax 750W / Platimax 850W and the Golden King Platinum design (Kingwin LZP-750) from Super Flower. The latter offering isn't just questionable in name, but the missing overcurrent protection and MOV are also a major drawback. As such, we wouldn't put that particular unit in the same category as the Seasonic; Super Flower products in general use cheaper quality. In price and quality Enermax Platimax is close to the Seasonic Platinum, but Seasonic clearly demonstrates better soldering quality and uses extensive EMI filtering. The Seasonic Platinum 860W is currently available for $220, which is $20 less than the best price we can currently find on the Enermax Platimax 850W. Given all of these factors, there is only one possible ending: the Seasonic Platinum 860W deservedly earns our Gold Editors' Choice Award for being as good as one's word—and in some cases, even better.

Performance Measurements
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  • theeldest - Friday, February 24, 2012 - link

    Maybe it's just me but I didn't see any pictures of the sleeved cables, eventhough they're specifically called out as being quite nice.

    "pics or it didnt happen"
    Reply
  • Stuka87 - Friday, February 24, 2012 - link

    I was just going to say the same thing. Was looking for photos of the cables but didn't find any. Reply
  • just4U - Friday, February 24, 2012 - link

    I mentioned that earlier.. still waiting for a reply from Martin. Reply
  • Earballs - Saturday, February 25, 2012 - link

    Going based on the picture of the 24pin.. it can't be /that/ nice. Reply
  • cyberguyz - Sunday, February 26, 2012 - link

    All of the cables on my Seasonic Platunum 860 came beautifully sleeved.

    No complaints at all with the quality of this PSU or its bag of goodies.
    Reply
  • aznofazns - Friday, February 24, 2012 - link

    This might seem really superficial, but the main reason I probably won't get this PSU is because the 24-pin ATX connector on the PSU side isn't compatible with the 24-pin cable on the X-650. When I first heard of the Platinum Series I was intent on getting one due to the longer 8-pin EPS cable (the motherboard tray on my V2120X is too long for my current one to be routed behind). This is important to me because I'm in the process of sleeving all my cables with MDPC-X for the purpose of aesthetics.

    Other than that, this PSU is amazing. Seasonic consistently delivers the very best power supplies in every wattage class, and even their budget offerings outshine the competition. Will the ultra high energy efficiency recover the extra cost over time? Probably not. Almost certainly not. But at least you know you're doing the environment a slight favor and can be quite confident that your components won't be fried by a faulty PSU.
    Reply
  • rtothedizzy - Friday, February 24, 2012 - link

    If you're happy with the x-650 and you don't need there extra power then there is probably no good reason to upgrade at that cost.

    But.....

    If you're going to all the trouble to individually sleeve the cables then "length of cables" isn't all that compelling of an excuse not to upgrade (if that's you're only reason). It's a very small additional investment in time and $$ to buy a crimper, some new atx pins, and a roll of 18 or 20 gauge wire and make new cables any length you need. It even makes sleeving easier since you don't have to get the sleeve over the connector pin (you can crimp it on after you get the sleeve on the wire). It would also let you get away with 1/16 sleeving instead of the usual 1/8.

    Just a friendly suggestion :)
    Reply
  • bigboxes - Friday, February 24, 2012 - link

    You do know they sell extraction tools that allow you to remove the connectors so that you can easily sleeve your wiring. Reply
  • rtothedizzy - Friday, February 24, 2012 - link

    Yes. I don't see how you would individually sleeve the cables (as I was talking about) without taking the pins out.

    ATX pins can be very difficult to get dense 1/16 sleeving over, whereas the wire with no pin is not hard at all to get 1/16 sleeving over.

    Or you can just go 1/8 and it doesn't really matter.

    My point remains though, if you're going to individually sleeve your cables then making longer cables out of wires and pins is not much added annoyance.
    Reply
  • elian123 - Friday, February 24, 2012 - link

    Can we expect platinum PSUs at lower wattages too? Now it only seems 750W and higher? Reply

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