Two weeks ago, I reviewed my first ever 80 Plus Gold certified power supply. Since then, I've been anxious to see more such units, wanting to know if this level of efficiency is possible to find at the same time as ultra high performance. Well, Seasonic read my mind and has sent me one of their new Gold units, the X-650, to play with.

Tomorrow is Thanksgiving Day in Canada. Will I be thankful I met this unit? Come on in and find out.

It is time once again to explore the strange and exciting world of power supplies here at jonnyGURU.com, and for only the second time ever I've decided to go digging for 80 Plus Gold again. You'll remember that a couple weeks ago I took a look at the OCZ Z series at 850 watts. That unit was the first unit in my lab to clear Gold, but in ways other than pure efficiency I found the performance a bit lacking in that unit. We'll see if today's outing with the brand new Seasonic X series at 650 watts delivers the goods in both efficiency and performance.

But first, let's look at the box some more and find some marketing to talk about. Wait... none of these panels are in English, here. Let me spin the box around some more.

Oh, here's something. Two small tables with specifications and load ratings for the unit. Single 54A 12V rail, eh? Internet, eh? Maude, eh? Sorry... I should turn the TV off while I'm writing.

Uh... guys? I think I found the English marketing section. It takes up the whole back of the box. Man... it's like they took a bazooka with some ink in it and went blasting away at the box. Let me see if I can organize this in a way that won't destroy the remains of my sanity.

• Seasonic Patented DC Connector Module with Integrated VRM * [Voltage Regulator Module]
  This patented full modular design minimizes voltage drop and impedance, maximizes efficiency and enhances the overall performance for cooling and reliability. *Patent Pending: US, CN, JP, TW & DE
  -Impedance? I think the word you want there is "resistance," Seasonic. Impedance is a function of AC power, not DC.
  • Benefits:
    • Minimizes resistance and voltage drop to maximize efficiency.
    • Consolidates and minimizes component useage to create space to improve airflow for better heat dissipation & cooling.
    • Extensive use of Al & SMD automation reduces human error and improves reliability.
    • Simple & ingenious design for a clean layout achieves unsurpassed quality and performance.
• 80 Plus® Gold Certified
  At least 87%, 90%, 87% efficient at 20%, 50% and 100% operating loads, respectively.
  -We'll have to see in the load testing part of the review how well this unit does in meeting these targets.
• Seasonic Patented "Hybrid Silent Fan Control" *
  An industry first, advanced 3 phased (Fanless, Silent, and Cooling Mode.) thermal control balances between silence and cooling. *Patent Pending: US, CN, JP, TW & DE
  -I'm not sure about this one. We've seen fanless before, and we've seen operation that ramps up the fan according to temperature before too. What's new and different here, exactly, that needs patenting?
• Sanyo Denki - San Ace PWM Silent Fan
  The superb high-grade San Ace Pulse Width Modulation fan pairs perfectly with the Hybrid Silent Fan control circuit for super low noise & cooling performance.
  -Interesting... I'm not sure fanless operation has been done with a PWM fan before. Maybe that's what they're patenting.
  • Benefits:
    • Reduces noise without increase in temperature.
    • Extends fan life by eliminating unnecessary rotation.
    • Optimizes heat dissipation at all times.
    • Fanless mode (0 dBA) provides unsurpassed silent performance.
• Active Power Factor Correction [99% PF Typical]
  Reduces line loss and power distortion.
• Highly Reliable 105°C Japanese Brand Capacitors
  Exceptionally reliable components extend product life.
• Conductive Polymer Aluminum Solid Capacitors
  Enhanced stability at severe operating conditions.
• Tight Voltage Regulation [±3%]
• High +12V Output
• Dual Sided PCB Layout
• 5 Years Warranty
• Full Modular Cabling
• Universal AC Input [Full Range]
• Multi-GPU Technologies Supported
• Patented Easy Swap Connector
• All-in-One DC Cabling Design

Whew, I think I'll stop there. I think I covered most of the salient points up there, anyway, though there are a couple of graphs and fancy pictures on the back of the box too I haven't mentioned.

Ah, at last it's time to unpack.

We get a power supply enclosed by a velvet bag, a user guide, a power cord, some screws, a case badge, and a folding double sectioned bag full of modular cables.

The user guide is well done on this unit, and is reprinted in a bunch of different languages.

And here's the unit itself, sans velvet bag. It's done up in a rough matte black finish.

These things are so much easier to photograph when they have no cables coming out of them. Here you can see the modular cable connectors. Let me get a better picture of those for you.

The modular cable connectors are all Mini-Fit Jr. style, and all are different from one another to reduce the chances of plugging something in where you shouldn't. Sharp eyes will notice that the ATX cable actually gets two connectors, rather than one single 24 pin monster. I presume this was done so the two rows of connectors could remain the same width.

Go for Gold! This is the sticker you'll be looking at should your case happen to have a window where the power supply goes.

A peek through the exhaust grill shows an interesting lack of heatsink material inside. I'm looking forward to taking this one apart on page four.

The fan side of the unit once again declares that the fan only runs when needed.

And here's our load table label for the day. As you can see, the unit promises that all but two watts of its total power output can be had solely on the 12V rail if needed. That's going to be tricky to test for in my crossload testing - it will require dropping most of the other rails to a zero load condition. Not all units like that. We'll have to see if this is one of those units.

An array of modular cables poses beneath the modular cable bag. Should you happen to have something that needs a 3.5" drive connector, Seasonic has provided a 5.25" connector adapter for you. Otherwise, Seasonic went with their usual differing length cable chains to assist in cable management. There are two total PCI-E chains, each splitting off into two cables at the modular panel connector.

Once again, we come to the fun part - the load testing. I'll be doing this the way I usually do this. That is, I'll hook up the Seasonic here to my trusty load tester and let it do all the work for me. The load tester in question is a SunMoon SM-268 automated test environment that is capable of electronically loading and testing ATX power supplies up to around a thousand watts or so. Joining it will be a Brand 4-1850 power meter, a USB Instruments DS1M12 oscilloscope, a dual probe thermometer, and a multimeter.

Starting things off will be a sequence of five balanced progressive and two crossload tests. These are done at room temperature, with loads ranging from 20% to 100% of full rated power for the progressive tests, and then loads unfairly lopsided toward either the combined 3.3V/5V rails or the 12V rail depending on which crossload test you're looking at. This will give us some idea on how well this puppy is supposed to bark, roll over, chase its tail, or lie down.

Following this, I'll run a special low load test. See, 80 Plus only starts testing at 20% of full power, going up from there. I want to see what happens at a much lower load than that. Why? It's quite simple... I'm a vicious evil power supply torturing madman. But really, it's because the lower you go down the power tree, the less efficient these power supplies get. I want to see how a Gold unit does at load levels below where 80 Plus starts at.

From there, I'll run my overshoot transient tests. That's where I go looking for turn on spikes that go out of ATX spec. What is the spec, you ask? Well, it's for those turn on spikes to stay below 10% above mean value, and nothing going into the negative voltage side. In other words, for the 5VSB rail, the spike can't go above 5.5V or below 0V.

At last, the real fun will begin. I'll lock the unit in my hot box and repeat the initial seven room temperature tests. That tends to sort the real power supplies from the Powmaxes.

*Unit remained in fanless operation for duration of test

Hello? Is this thing on? Such were my first words when I powered up this unit for testing. The fan twitched and immediately stopped. It didn't turn on again until test three. And then it turned off again for crossload test one. It seems that Seasonic wasn't joking about this being a quiet unit... you just can't get much quieter than fanless. I like that the fan twitches just to let you know the unit isn't dead or something.

You say the efficiency numbers are mighty impressive looking? Well, I have to agree with you on that one. With the lowest number still pushing 90% in the progressive tests, this unit is the new efficiency champion around here. I simply haven't tested anything as efficient across the board as this unit. Just look at the heavy 3.3V/5V crossload test... I have trouble getting these units to beat 80% in that test, never mind 87.5%! If all you care about is efficiency, you can pretty much stop reading right here and go buy one of these right now.

Me, I care about voltage regulation too, so I'm continuing on. See those numbers up there? I do have to admit I have seen better stability than that in the past. But, if that can be considered bad news, here's some good news - I haven't seen too many units do better. The unit is holding to Seasonic's 3% promise. Indeed, the 12V rail is doing 1%, while the others are within 2%. That's exceptional.

In looking at the low load test results, I'm starting to wonder if I shouldn't have put a big red warning logo above it to warn you to sit down first. I heard crashing noises - I hope you guys are ok. Personally, I was already sitting down when I did the math for this table, else I'd be in the hospital right now. There just isn't room for a six and a half foot tall guy to fall safely in this room and not take serious injury.

88.8% at a below 10% load level. Good golly. Maybe I should go lie down for a while... I'm getting light headed again just looking at that number. This here Seasonic platform seems hell bent on breaking records today.

Overshoot Transient Testing - Seasonic SS-650KM
VSB On	VSB to Full, 12V	Off to Full, 12V

Sadly, this here Seasonic platform has just come up as merely average to slightly above average in this test. No, none of these spikes are getting up to that 10% over mean value level, but they aren't really that well suppressed either. Past Seasonic platforms like the M12D were better performing here. This is nothing you should worry about, and this will not have much if any impact on the final score, but it's a wee bit of a letdown to go from the efficiency numbers to this.

Now it's time to crank up some heat. My hot box will help with that - it's an ATX case that has been modded to get the heat output from the SunMoon's exhaust fan ducted right into it. I've seen this thing hit 60 degrees in past test sessions on really big units. But because this is not a really big unit, I'll have to turn off the intake and exhaust fans in the box and hope that we see ambient temperatures high enough to make the Seasonic scream.

*Unit remained in fanless operation for duration of test

Well, I guess I'm the only one screaming in here, and it's due to excitement. In test two, the X650 is actually more efficient than it was cold, and even test five barely sees any drop. This platform is really outstanding when it comes to pure efficiency.

Know what else is outstanding? The fact that the unit was still fanless in my hot box. Sure, it only stayed off for test one, but let me be honest here - I've never had a fanless unit stay fanless in the hot box. It just gets too hot for most fanless units to stay that way.

And look - I did get the unit up to high ambient temps. Forty eight degrees, to be specific. Forty eight marshmallow roasting, butter melting, finger burning degrees, to be prolific. For-ty eig-ht de-gree-s to be sporadic. But look - the X650 didn't mind one bit. Why, it barely added any of its own heat to things, only hitting fifty nine by the time test five was over. For a while there, I thought the thermometer was faulty. Even better, the fan was barely spinning at all through the whole session.

Going back to the voltage readings, it only gets more awesome. But, slightly less awesome than that area was cold. The 3.3V and 5V rails are about as stable as they were cold, but the 12V has now lost its grip on that 1% number and is riding slightly above it here.

Let's take a look at the ripple and noise scope shots.

Oscilloscope Measurements - Seasonic SS-650KM
Test #	+3.3V	+5V	+12V
Test 1
Test 2
Test 3
Test 4
Test 5
Test CL1
Test CL2

Avert your eyes! The above shots are too awesome for human eyesight to tolerate! Yes, folks, this here Seasonic platform has decided to out-awesome just about everything I've tested to date. With ripple and noise under 20mV on all main rails from tests two to five, this unit joins the very best of the best for ripple and noise suppression. But, there's a bit of weirdness going on in test one on the 12V side of things. Must be a side effect of the design. Still, at 30mV for that test, there's nothing to complain about there, either, and it's unusual for a unit to actually get better here as the tests go along.

Now, I'm curious. I have to see what this thing looks like under the hood.

As the box promised, the PWM fan is this Sanyo Denki model.

Wow - that looks really different in there.

Transient filter starts with this here integrated line filter and AC receptacle.

The underside of the main PCB looks almost as odd as the topside. See those transistors up there near the top center of the picture encrusted with thermal compound? Those handle the 12V output of the unit and are IPD036N04L parts. Each one can take a whole lot of continuous drain current, and even more in pulsed mode. They are heatsinked by the PCB itself, and by the power supply case via some thermal pads.

Here's the integrated VRM and modular connector panel. Hey... what's it staring at? Those are Nippon Chemi-Con polymer capacitors there making up the nose and moustache.

The working parts of the VRM center around an APW7159 controller, and each of the 3.3V and 5V rails get two APM2510N's and two APM2556N's. Power to the VRM comes off the main 12V supply for the whole secondary.

Switching transistors are two W20NM50FD's. PFC is done with three 20N60C3's, a diode, and a controller I couldn't ID due to it being a surface mount part too hard to read the number off of.

All capacitors are Nippon Chemi-Con. Transient filter continues with two coils, two X capacitors, a MOV, and two Y's. Bridge rectifiers are GBJ1506 parts.

Supervisor chip here - a PS223.

Those two goalposts coming off the main PCB are actually heatsinks used to help dissipate the heat from the 12V output parts on the underside of the PCB. In the bottom right, you can see a CM6901X LLC resonant controller that forms the backbone of this platform. Hmm... that chip switches between FM and PWM modes during operation. I betcha that's what we saw in the scope shots for test one - the unit was operating in a different mode at that level. Cool!

Performance (40% of the final score) - the X series from Seasonic is their new top of the line platform. As such, I expected the performance to match up accordingly. I was not disappointed. With the best efficiency I've seen to date combined with outstanding rail stability and ripple and noise suppression good enough to give server grade units nightmares for months, Seasonic has a winner among winners here. 10.

Functionality (20% of the final score) - with completely modular topology, not much can be said against the cabling on this unit. No, not many people would find the need to unplug the main ATX cable from the unit, but I can't really say it's that big a deal as stable as this unit held its voltages. And fanless operation is nice... especially when this unit was able to remain fanless for a whole test in my hot box. 10 . Man, I'm throwing those tens around an awful lot lately.

Value (30% of the final score) - this unit has yet to make its way to the market in large numbers, so I'm going to be lazy and go look at Newegg. Let's see... $179.99. You know, that's actually a good price for something like this. Yes, the Corsair HX750 is a bit cheaper, but this unit is more efficient in general with slightly better build quality. But... uh oh... the 750W version of this unit is $20 more money. One hopes that these prices will go down just a bit, because that's getting to be a little much. 8.

Aesthetics (10% of the final score) - I've always liked matte black. But while this unit is good looking, I've seen a couple I've liked better. 9.5

Summary

Lately, it's gotten to be much harder for a power supply company to get ahead. The competition is fierce, and it's only going to get more so as time goes on. Seasonic decided that in the X series they were going to go out on a limb, design a new platform from the ground up, and then toss it into the shark tank that is the power supply market. And you know what? If I were a company swimming in that tank, I'd watch my tail fin. This is one really impressive platform Seasonic has here. It's incredibly efficient, it's incredibly stable, and it's hungry for market share. That's a deadly combination for the competition.

The Good:

• goes fanless until it heats up... and fanless operation is actually attainable in a warm computer case for a change
• efficient
• efficient
• efficient
• did I mention it's efficient?
• stable regulation
• fully modular
• excellent ripple and noise suppression

The Bad:

• you'll want to buy two... or three... or four...

The Mediocre:

• no TV and no beer make Wolfie something something