Seasonic M12D 850W: DC-to-DC Perfection?
by Christoph Katzer on November 26, 2008 12:00 AM EST- Posted in
- Cases/Cooling/PSUs
Internals
Opening the casing reveals a completely different design than the usual Seasonic PSUs. It reminds us of the design we saw from Acbel in the Cooler Master UCP series, as well as Impervio units from OCZ and Silverstone. There are two large heatsinks that we saw earlier, plus a smaller one on the primary side. The filtering stage is located on a small sister PCB shielded with a copper plate, at the back of the secondary side. Power then routes through a cable to the main PCB into additional filtering, and from there into the PFC stage. There are two main Nippon Chemi-Con capacitors, each rated at 390µF and 400V. These capacitors are also rated at 105°C, which is higher than most companies use.
Moving over to the secondary stage, we find additional Nippon Chemi-Con capacitors between the cables that are attached to the PCB. Below the heatsink is another sister PCB that includes the DC-to-DC circuit. We think the Enermax design was a little better here, since it also contains the cable management sockets. That allowed Enermax to clean up the main PCB, whereas the Seasonic PCB looks a little cluttered. Regardless, the end result still works well and delivers good performance.
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sprockkets - Wednesday, November 26, 2008 - link
Very bad waveform with very high frequency components? The "waveform" exists since it cannot perfectly make a flat line voltage.Besides, the ATX12V 2.3 spec allows 120 mV ripple for all 12V lines and 50 mV ripple for the 3.3 and 5V lines. It is very well within spec, and consider that these ripple specs are stricter than previous versions of the ATX12V spec, you are going to be fine.
valdir - Wednesday, November 26, 2008 - link
Waveform exists since we are looking and measuring it... and there are good and bad ripple and noise waveforms on the DC rails, just compare with Antec Signature or Corsair 750W or Enermax Revolution or... definitively a very bad waveform.These waveforms are more like very high frequency noise covering ripple and this is not good, since on the PSU's DC rails we should see ripple and not the same noise level.
mindless1 - Saturday, November 29, 2008 - link
Actually it won't make a bit of difference in use. The day a little bit of ripple or it's frequency matters, will be the day we all start using linear PSU again.fri2219 - Wednesday, November 26, 2008 - link
Why does Seasonic insist on putting crappy ADDA fans in 150.00+ units? For the same price, they could at least source from Panasonic or Yate Loon.That ticking sound in the "heavily undervoltaged fan" (nice heavily murderaged of the englished language, there) is incredibly annoying for those of us who haven't destroyed our hearing by playing our iPods at 90db every day for the last 5 years.
mindless1 - Saturday, November 29, 2008 - link
WTF? Yate Loon is the bottom of the barrel, ADDA is mid quality. If you want a yate loon on your case wall it's not so bad but those fail pretty frequently when placed horizontally in a PSU.sprockkets - Wednesday, November 26, 2008 - link
Perhaps you can re-read page 1 where it says it uses a Sanyo Denki fan.And, what is "murderaged" spelling hypocrite?
Slash3 - Wednesday, November 26, 2008 - link
Wooshed.JarredWalton - Wednesday, November 26, 2008 - link
FWIW, that was another error with the speech-recognition. Dragon NaturallySpeaking does so well that sometimes I miss errors in dictation. Apparently, it thinks "undervoltage" is an allowable word, but I know I said "undervolted". Whatever.In case you're wondering, Christoph is not a native English speaker, but he is fluent in at least English, French, and Chinese -- besides his native tongue of German. Feel free to critique his use of a second tongue; me, I'm happy to speak English, Danish, and some German. Anyway, I do pretty heavy editing of his text to clean up the English, but errors slip through on occasion. I was pressed for time on this one (had to run off to the airport) so I didn't give the final text a second proofread.
RallyMaster - Wednesday, November 26, 2008 - link
"That's not entirely wrong, as PSUs are one of the components most people only think about when their old unit sales, or when building a new system."What does "old unit sales" even mean? Are you sure you're not saying "old unit fails?"
Spoelie - Wednesday, November 26, 2008 - link
Page 1"The PSUs are also supposed to have very tight voltage regulation in the future only Japanese manufactured capacitors."
I'm not quite sure what to make of that sentence.