Seasonic M12D 850W: DC-to-DC Perfection?
by Christoph Katzer on November 26, 2008 12:00 AM EST- Posted in
- Cases/Cooling/PSUs
Temperatures, Fan Speed, and Acoustics
The temperature results of the Seasonic M12D are another area where it excels, surpassing most other power supplies. When you compare the temperatures to the increasing speed of the fan, you can clearly see how well the design works. Many other power supplies ramp up fan speed even when it's not necessary, and frequently higher fan speeds and increased airflow barely manage to keep temperatures in check. In contrast, the M12D stays under 50°C at all times; there's a jump in temperature on the secondary heatsink between 20% and 50% load, but it's not enough to actually require a significant increase in fan speed. Once the fan does begin to speed up, however, we immediately see temperatures begin to fall off, showing that the heatsinks are working exceptionally well.
With loads of up to 50%, power output generally stays below 400W and this power supply is virtually silent. Only beyond 50% load is the fan begin to kick in, and as we saw above it does a good job at keeping temperatures in check, reaching a maximum 2300RPM. Seasonic is a bit conservative at higher loads, since the temperatures are still more than reasonable, but they are proud of the engineering that has gone into this design.
At maximum loads and fan speeds of 2300 RPM, it's no surprise that noise levels aren't great. Maximum acoustic noise reaches 31dB(A), which you can definitely hear -- although as usual, creating a load of 850W generally means a lot of noisy graphics card and CPU fans as well. Seasonic prefers to take a conservative approach and avoid overheating, which is good for end-users and component longevity. Given that few users will put such a heavy load on their PSU, however, noise levels of only 17dB(A) at up to 400W are practically undetectable -- it's definitely at the lower boundary of what our equipment can measure. There is however a small ticking noise that can be heard from the heavily undervolted fan, which is common with fans that used normal voltage regulation instead of a PWM controller. (Antec has the patent for PWM controllers in PSUs.)
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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.