Seasonic M12D 850W: DC-to-DC Perfection?
by Christoph Katzer on November 26, 2008 12:00 AM EST- Posted in
- Cases/Cooling/PSUs
Efficiency and PFC
We measured up to 89% efficiency using 230VAC, which is near the top of our efficiency charts. A few power supplies have managed 90% efficiency, but as we mentioned elsewhere a difference of 1% isn't very significant. Looking at lower input voltages, efficiency is still good but the curves aren't quite as nice, with 120VAC reaching 88% efficiency, but only for a very small range of loading. After reaching the peak efficiency, the curve on 120VAC drops pretty quickly.
The M12D doesn't support 90VAC, which is listed on a sticker next to the AC input. Normally we don't have any problems testing with 90VAC, but this particular power supply definitely doesn't work properly; voltages went up and down like a roller coaster, so we used 100VAC instead of the regular 90 for the above charts. At 100VAC, the efficiency curve looks even worse, reaching a peak value of 86% at 200W and then immediately dropping. Running a load of just 200W on an 850W power supply definitely wouldn't be the best use of your money, so if you need a lower input voltage we would look elsewhere.
Getting back to where this power supply really performs well, 230VAC delivers great results. Even with just 10% load (85W) the M12D still manages 85% efficiency, which is a fantastic result. In Europe, you can run everything from 80W up to nearly 900W and still stay above 85% efficiency. 120VAC is decent as well, staying above 83% efficiency from 80W up to 800W.
We have seen much better PFC results in other power supplies; particularly under 230VAC, this unit doesn't perform that well. It reaches a maximum of .98 -- still good, but not what most people would expect from a high-end unit. PFC with other input voltages is also lower than what we normally see.
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JarredWalton - Wednesday, November 26, 2008 - link
I have no idea... I think I said "and they feature" perhaps? Heh. Go Dragon!Slash3 - Wednesday, November 26, 2008 - link
Argh! The fingers, use them! :) It's probably faster, too, after correcting two dozen mis-transcribes.JarredWalton - Thursday, November 27, 2008 - link
I would... but carpal tunnel issues make it a problem.BikeDude - Saturday, November 29, 2008 - link
Sorry to hear about your carpal tunnel issues.But I have always thought that such issues stems from mouse usage. So at work I use my left hand for moving the pointer, and at home the right hand.
Using a keyboard should not normally be much cause for concern?
JarredWalton - Wednesday, November 26, 2008 - link
Blame the editor (me) and my speech-recognition. Should have been "fails".PrinceGaz - Wednesday, November 26, 2008 - link
On page 3, about the cables, the speech-recognition software seems to have made another error[/quote]Most of the cables are detachable and come in an extra bag Seasonic provides. The 24-pin ATX connector, 4-pin ATX12V and 8-pin EPS12V connectors, 260cm 6-pin PEG connectors...[/quote]
I think that should read two 60cm 6-pin PEG connectors.
Zoomer - Thursday, November 27, 2008 - link
I thought someone was supposed to proof-read these. ;)feraltoad - Wednesday, November 26, 2008 - link
What speech recognition s/w do you use Jarred? Do you use it just for large amounts of text entry or is useful for other things like quick posts like this. Does it make things quicker? Or does fixing the errors eat up a lot of time? I guess you just save time and don't fix those errors. haha j/k!feraltoad - Wednesday, November 26, 2008 - link
Oh. U use Dragon. Well, other questions stand!