Seasonic S12II: 330W to 500W of Silence
by Christoph Katzer on September 14, 2007 4:00 AM EST- Posted in
- Cases/Cooling/PSUs
The Inside
330W version
500W version
Once the power supplies are open we are greeted by this very simple looking PCB. The first impression isn't all that great as the heatsinks look small, the component arrangement seems a bit haphazard, and the coloring almost makes things look dirty. However, looks can be deceiving. The first visible difference between the two power supply models can be seen in the different coils, main capacitors, and transformer. Since the design is the same and the components are from the same manufacturer, we will continue our discussion focusing on just one of these power supplies.
The filtering stage seems to be well arranged by Seasonic; it's starts on the small PCB at the AC inlet and extends to the upper side of the main PCB directly in front of the exhaust area. Seasonic has always taken a different approach with their heatsinks, which is very simple and almost seems cheap. Instead of using more expensive extruded aluminum, they just use metal plates where the fins are punched out and bent to the side. This way is by far the cheapest way to make a heatsink, and while it might not be as efficient as an aluminum design, with the high efficiency components Seasonic uses they should not have any problems with overheating.
There's also something to be said for their smaller heatsinks: large heatsinks tend to block airflow, and while the heatsinks might stay cooler surrounding components could actually end up being hotter. With plenty of open space, Seasonic's somewhat unique approach to power supply internals may be part of their reason for their excellent reputation of silence. Of course, having the power supply that isn't rated to provide 750W or more also helps with managing heat.
330W version
500W version
Once the power supplies are open we are greeted by this very simple looking PCB. The first impression isn't all that great as the heatsinks look small, the component arrangement seems a bit haphazard, and the coloring almost makes things look dirty. However, looks can be deceiving. The first visible difference between the two power supply models can be seen in the different coils, main capacitors, and transformer. Since the design is the same and the components are from the same manufacturer, we will continue our discussion focusing on just one of these power supplies.
The filtering stage seems to be well arranged by Seasonic; it's starts on the small PCB at the AC inlet and extends to the upper side of the main PCB directly in front of the exhaust area. Seasonic has always taken a different approach with their heatsinks, which is very simple and almost seems cheap. Instead of using more expensive extruded aluminum, they just use metal plates where the fins are punched out and bent to the side. This way is by far the cheapest way to make a heatsink, and while it might not be as efficient as an aluminum design, with the high efficiency components Seasonic uses they should not have any problems with overheating.
There's also something to be said for their smaller heatsinks: large heatsinks tend to block airflow, and while the heatsinks might stay cooler surrounding components could actually end up being hotter. With plenty of open space, Seasonic's somewhat unique approach to power supply internals may be part of their reason for their excellent reputation of silence. Of course, having the power supply that isn't rated to provide 750W or more also helps with managing heat.
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n0nsense - Sunday, September 16, 2007 - link
Btw, can you add 1 minute record of ambient, idle PSU, typical load PSU and full load PSU noises @ ~1 meter ?this will be much more useful then just dba levels.
vijay333 - Friday, September 14, 2007 - link
lol. so many people requesting seasonic reviews lately and not a peep from them yet. these units are probably suited for budget systems but the added expense due to the seasonic moniker may be better applied to future-proofing and getting a higher wattage model from a less "esteemed" brand.yyrkoon - Saturday, September 15, 2007 - link
Not everyone requesting a review HAS to comment on the review. I could have been the first poster in this comment section on this article, but decided that the article was good enough to not comment. Granted I think for a lowly 500WATT PSU the Antec Earthwatts 500 PSU would be a better bargin(which I already own).customcoms - Friday, September 14, 2007 - link
I'm waiting for a Corsair review from you guys, since they are based off Seasonic psu's and can provide higher wattage. Also, people looking at the Seasonic 500w model would also probably be looking at the Corsair HX520.My HX520 is silent (granted I have like 8 case fans+cpu+ram+8800GTS, so noise of the psu is of little concern) and as an added bonus its modular.
kmmatney - Friday, September 14, 2007 - link
There is a new 550W Corsair available now, at a lower cost:http://www.newegg.com/Product/Product.aspx?Item=N8...">http://www.newegg.com/Product/Product.aspx?Item=N8...
Christoph Katzer - Friday, September 14, 2007 - link
Will have Antec and Corsair very soon but I can tell you already they cannot stick up to the originals.n0nsense - Sunday, September 16, 2007 - link
as I can see, Corsair HX520, HX620 are better.the 12V much more stable + modular cables + 0 noise.
but may be the Corsair's VX (budget) should be reviewed too.
Chunga29 - Friday, September 14, 2007 - link
I want to see one of the X900 Seasonic PSUs tested now. See how Seasonic does when they have to deal with about 2X the power demand. Though, that design looks completely different so I expect silence isn't the goal in that case. Seeing the M12 700HM results would also be useful. The S12II is at 28dB at full load, but dealing with another 200W could mean quite a bit more noise.I would also be curious: can these PSUs handle higher loads than rated? I mean, I've heard rumors that something like a Seasonic 330W sold under a different label would get rated probably ~25% higher, so maybe 420W. That would make the S12II 500W potentially equal to other ~650W PSUs, *if* there's any truth to the stories. Just a thought, but I'd like to see testing push PSUs beyond the rated output to see what happens. Probably best to save that testing for the end, in case the PSU dies. LOL. But going 20% beyond the rating could provide interesting results.
Christoph Katzer - Friday, September 14, 2007 - link
I was thinking about to add this kind of test. Last week I was talking to Paul from H about it and just for fun tested the Infiniti and got 1000 watts of load out of it. That might be surely a nice thing if more PSUs would perform like that.poohbear - Sunday, September 16, 2007 - link
chris are u saying the corsair hx series (which are designed by seasonic) can't measure up to original seasonics? they're pretty bad ass psus, i own the hx520, i can't imagine anything more silent than this unit?! or are u talking about efficiency? anyways, thanks for the review, seasonic rocks and my corsair is testament to that..:)