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- Date:
- Friday , August 13, 2010
- Author:
- Paul Johnson
- Editor:
- Kyle Bennett
- Google +1
Seasonic X-Series: X-400FL Silent Power Supply Review
Seasonic, long known for making excellent power supply units has gone silent. Not just quiet, silent. It's new 400 watt unit comes to the consumer complete with no fan. Now let's see if the new silent Seasonic is worth your hard earned cash.
Conclusions
The Seasonic X-400FL represents the 5th Seasonic power supply we have reviewed to date, and in the 100 reviews we have posted on power supplies it also happens to represent the first fanless unit we have reviewed. While Seasonic has a very good reputation for designing and building quiet power supplies, this unit should prove to be the quietest unit we have reviewed to date given its fanless nature. However, with no fan we have to wonder if this unit will be able to handle the heat, or if it will have to get out of the kitchen. Let's move on and see what this unit is all about!
HardOCP’s testing methodology is intended to very much push power supplies to their advertised wattage rating in temperatures that will represent some of the hottest computer enthusiast cases. So if a unit passes all our testing it is definitely not something to take lightly. In fact we expect more power supplies to fail our testing than make it through unscathed.
Build Quality
The overall build quality of the Seasonic X-400FL is simply excellent across the board. This unit, like others in the X-series line, never showed signs of corners being cut or compromises being made. This is particularly important because of the one key way in which this unit differs from the previous X-series unit, it is fanless. Due to this fact, this unit is heavily perforated in order to aide in cooling but even with this heavy perforation the unit looks strikingly like the X-750 and follows its external build characteristics closely. The black and gold motif is very distinguished and very tough. The cables are, however, a good bit longer than what we would expect from a unit that is supposed to be geared towards HTPC type applications. The interior of the unit is once more exceptionally well built and a very modern design with excellent components. The capacitors are again provided by Nippon Chemi-con which is excellent and covers both the primary side and the secondary side. The main changes found with this unit compared to the X-750 are due to its capacity (such as the single capacitor on the primary side) or due to the removal of the fan (new heatsink design on the secondary and heatsink on the modular PCB). Otherwise, all of the excellent features and build quality points of the X-750 can be found again on this unit. In addition to all of that, this unit comes backed by a 5 year warranty which is good to see.
Load Testing
The results for the normal load testing with the Seasonic X-400FL at 120v and 100v were outstanding. I mean simply outstanding. The voltage regulation for the X-400FL was excellent, just like with the X-750. With the X-400FL we saw a total change of just 0.10v on the 12v rail in our testing while the minor rails saw changes of just 0.03v over the loads tested. These are simply outstanding results. Continuing its run of tremendously solid results the X-400FL posted efficiency values that ranged from 87.69% to 92.44% at 120v and 87.02% to 91.63% at 100v! Those are the best results we have seen to date, and are once more just excellent. When we move on to the Transient Load Testing though, we do see this unit's one weak point. Like with the Seasonic X-750 before it, the X-400FL Transient Load Testing results rate as a pass. However, the results are not outstanding in this regard. The loaded 12v rail saw peak changes of ~400mV in both tests. The 5v rail, however, saw peak changes of ~100mV when directly loaded or not. These results aren’t great, but there are some reasons for this unit's results today that do excuse part of this result and some that do not. Of those that do excuse part of these results are the fact that this unit is just a 400W and as such the transient loads represent a much larger portion of this units capacity than it does for larger capacity power supplies. The reason that does not excuse these results, is the fact that the unit uses an LLC resonant DC-DC design which is great for efficiency but typically is less than stellar for Transient Load Testing characteristics in our testing. In the end though, it does pass so we just have to keep it all in perspective.
DC Output Quality
The Seasonic X-400FL passed the DC Output Quality tests today. Ok, it didn't just pass the tests, it excelled in those tests. Ok, perhaps excelled is an understatement. Maybe it would be more accurate to say that it ran circles around the tests like a little child taunting a playmate. During load testing the X-400FL managed to post peak trace amplitudes of just ~20mV on the 12v rail and ~10mV on the minor rails. On top of that, those values were the same for Tests #2, #3, The Torture Test, and Test #4. Yeah, not only did this unit post outstanding DC output quality it posted the same excellent DC output quality results no matter the load after 25%. That is just outstanding, simply outstanding Seasonic. Kudos!
Noise
The Seasonic X-400FL is fanless, which, unsurprisingly, made this unit silent. I am sure it would make some noise if you dropped it on the floor though.
Paul's Thoughts:
The Seasonic X-400FL is everything the X-750 was and then some. The voltage regulation was awesome, the efficiency excellent, the noise profile......ok its fanless so we can skip that part. Where this unit does trail the X-750 is the Transient Load Tests but this unit is a good 350W smaller in capacity so this result was really a given from the get go. This all sounds amazing right? So what is that other shoe that is ready to drop? You know there is always another shoe ready to drop when you see awesome results like this. Oh, it's the MSRP of $139.99! Ouch, this is only a 400W unit being sold for the price of many quality 750W units. After that burn settles for a minute it is important to look at two things, what do you get for that price and what do similar units cost. First off, you get an outstanding X-Series unit without a fan so it is dead silent. So what do similar units cost? Well the Silverstone Nightjar 400W is ~$160 if you can still find it and the FSP Zen 400W is e-tailing at $110. Now compared to those units the X-400FL's demonstrated performance beats those units advertised performance which makes that $140 MSRP seem like a deal. Even sweeter is the fact that this unit will likely street for less than that MSRP. As such, the X-400FL represents an awesome deal relative to its peers, and an amazing performer in general. Just because a product is expensive that does not make it a bad deal or unworthy. Sure the recently reviewed Silencer MkII 950W was a horrible deal as it was ridiculously expensive compared to other similar units and to make matters worse it was not as good as those units. The X-400FL on the other hand is ridiculously expensive compared to other 400W units, however it smokes those other units like nobody's business and has a unique feature that makes that price tag a much easier pill to swallow. Quality and features such as those exhibited by the X-400FL don't come cheap. Sometimes you have to pay to play and the X-400FL is just one of those times, but when you play with the X-400FL it is one fine game.
The Bottom Line
Before even beginning to sum this unit up it is important to remember one thing; the X-400FL is a niche product meant for only a small subset of users. Niche products often are more expensive than more broadly applicable solutions for various economic reasons but when the chips are down the X-400FL is a niche product that just kicked all of its competitors in that niche, and many that aren't even in that niche, to the curb. The X-400FL posted simply excellent Load Testing results, the best efficiency we have seen to date, AMAZING DC output quality, it was silent throughout testing, and it was built like a tank. Sure the Transient Load Testing results weren't great, but this is a 400W unit and in relation to other 400W units it did not do that badly (and it kicked all of those other units' shiny metal butts in every other category). With an MSRP of $139.99 the X-400FL is not a inexpensive power supply. In fact it is downright expensive, but at least for that $139.99 you are getting what is likely the best 400W unit on the market and it is silent. Quite simply put, for users looking for a quiet power supply solution it just doesn't get any better than the Seasonic X-400FL, expect maybe for the X-460FL which we have yet to test.
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