OMG
How/why did they let that one slip through?

great review mike

Well I doubt it's such a concern if the fan is pretty quiet at low speed. Also it's far far better than fans that spin up and then stop constantly. Much better to have a consistent noise signature when possible.

I think they could've done a lot better than that. I sure wouldn't like to shell big bucks for this PSU and having to hear that bloody 60mm fan at full blast after a session of gaming.

Therefore that note on the back should read "Temperature activated fan. Rotates only when required, but never stops (it's an infinite loop of doom!)"



Slight or not... it's never good.

"Also it's far far better than fans that spin up and then stop constantly"

And how would that happen in this case? If the PSU was under 300W+ load the 60mm would start. If the load dropped below 300W the 60mm fan stops. That ain't gonna happen every 5min!

It's certainly not ideal, but I doubt it would be full blast when you drop down to lower power. See the 300W result where both fans are going and the SPL is only 25. And if you have such a high power system, it's certainly not going to be absolutely silent without extra work. Either way it's still basically the best high power psu out there and far quieter than any other.




It won't happen in this case! That's why it's good it doesn't stop near the same voltage!
and it's not that hard...just happen to have something right on the borderline between fan starting and stopping. It's easy to do with a fan that starts and stops at the same voltage, impossible with this fan. Now I do think it should stop at the lowest voltage point of 3.9, that would make a lot of sense... but a minor quibble at best. Far better off to avoid getting to such a high wattage under load in the first place....no need for p4's, high end ATI cards, and SLI I hope

Like most things, the M12s are not perfect. For their intended market, whatever complaints we silencers might have are pretty trivial. The buzzing, the extra 60mm not stopping -- these happen at too low a power load and too low a loudness level for them to be significant in a high end gaming system.

The extra cooling provided by the 60mm has to be fairly significant and worthwhile for high power applications -- otherwise, why would Seasonic put that in there? This is difficult to prove without actually checking the temperatures of key electronic components in the PSU w/ and w/o the 60mm fan.

For silence enthusiasts, yeah, it's more than we need for power, and that 60mm fan isn't needed either. 300/400W power versions of the S12+ with the detachable cables of the M12 would be just about perfect. Seasonic, are you listening?

The review wasn't the kind of 'buzz' i was expecting, pardon the pun. Really, thats the kind of stuff you get with oem psus, not Seasonic. And buzz is exactly what i'm expecting to eliminate with the M12. I'm really hoping with a 500w I don't get buzzed, same as in the samples.
Has the smaller heatsink really done any good, or did it just cut building and shipping costs?!

[EDIT] Just noticed it's 2cm longer, if anyone tries it on the P180 give some feedback plz. The 500w phantom managed (barely) but thats not modular. I'm guessing since the connectors require some space, I would have to go without the lower chamber fan, which could prevent the 60mm fan from ever turning on.

puscifer --

Our market system is all about "choice", right? If you're concerned about the extra noises we documented, and you expect/hope for the 60mm fan to never turn on, this suggests that your power needs are not that high. In which case, why even consider the M12-500? The S12+ 550 is just as powerful, standard length, and it's quieter. Possibly the quietest of all the Seasonics. And it's easy to manage the extra cables in a P180.

Tuff when you can't get both worlds, the efficiency of the 430 and silence of the S12+. The +5% higher idle efficiency would make a difference in my 24/7 system.
The main problem is here in Portugal we haven't gotten the S12+ yet, just the M12s. One store carries the 430w for €85, but i think its the 1st unsleeved series without the 6pin pci xpress cable, so i'll probably wait and choose the -5db for the 5% efficiency.

BTW, thanks for the your great work in reviewing, it's been a great help.

that disconuity in the table for spl @ 65W, is this due to the buzzing you have mentioned?

Yes... but it should be 24 dBA, not 25... (just corrected)

Mine doesn't, but I don't have a high gaming rig, only a AM2 X2 3800+ (undervolt at 4x Vcore 0.900V most of the time), BFG 7900GS (underclocked 250/660 and cooled by Pentagram XC-80 Cu at +5V).
For my curiosity I've @ CPU to 2400MHz, GPU 600/800 and I ran Orthos & rthdribl at the same time in the middle of the night. I don't hear nothing from my PSU.
Rest of my setup: CPU box cooler with fan at 1300 RPM, case Antec SLK 3000B dampened with Nexus DampTek, TriCool fan on low. Really really quiet.
And regard to that little fan, according to this site in my "frenglish" I understand that on M-12 500/600 that little fan isn't necessary because (for production costs) they didn't change the PSU chassis.

Typo patrol - caption on your first picture:

"Four capacity points: 500W, 600W, & 700W."

Burebista, that is a very interesting tidbit, good investigative work. This means that M12-500/600W owners can disable the 60mm fan if they wish without fear of impairing the function of the PSU (although voiding warranty of course).

Not sure that I'd do that. Why not just get an S12? It's not like cable management is such a hardship if you choose a decent case and have followed any of Ralf Hutter's instructional tidy wiring system builds.

Agree with MikeC. In fact it seems that little fan is working on M-12 500/600 but only in extreme conditions.
On same site they cover 120 fan with a sheet of paper and the little fan start spinning. They measured 42.8 dBA instead 41.5 dBA with 120 fan (at 20 cm).

Isn't corsair(?) or one of the other RAM-companies comming out with a rebadge of thei seasonic, without the extra fan? That might be worth a try.

AtW

Strange. My 60MM stopped spinning when I came back down from the big loads (I cycle the PSU down to a low load before shutting it off so it can cool down.)

Also, my buzzing didn't go away with greater load. It always buzzed, but it was very subtle and couldn't be heard through the steel panels of the case. So this seems to be more of a quality control matter than a characteristic.

Hi to all, I am new to the forum and sorry for my bad english.

I read the review and I am so sad, just when i tought that i bought a top PSU
very silent, I read all this bad comment about the noise..

Saturday I will build my new PC

Lian Li V1200+
( change the 2 x 120 with 2 x 120 noisblocker 17db )
E6600
Zalman 9500
XFX 7950GT XT ( passive )

I hoped that the seasonic m12 was a right choice but now it is too late to change.

Sorry de OT, but your system will never make that little fan to spin.
In fact a S-12 330 should handle fine your rig.

so it will be super silent ? hmm hope so and what about the buzzing on 12V ?

IMO for high power PSUs that can't be quietly cooled by just one 120 mm fan placed at the bottom, a different fan setup would work:
Two 80 mm fans on the back panel (where the 60 mm is placed in the M12).
The PSU width would exceed a bit the specifications, but IMO it would be worth it.
The heatsinks could be beefier without disrupting much of the airflow, since air resistance would be smaller.
And as we all know, two fans generate less noise than one fan for the same airflow.

Yes, Corsair HX620.

For me, it's not immediately apparent that 2 80mm fans should be more efficient at moving X CFM than one 120mm. With 2 fans you are getting double the motor/bearing noise, also they are a smaller diameter fan so they have to spin faster than a 120mm moving the same amount of air; but maybe because there are two of them it mitigates this somewhat?

I agree that it's not clear about 2x80mm vs 1x120mm -- but the kind of straight through airflow Tzupy suggests would be a lot more effective for cooling than in the typical 120mm fan PSU -- assuming a reasonable degree of care in HS fin design. In fact, I'd say it about the perfect scenario -- except you would have the slightly higher cost of 2 fans, and perhaps a slightly wider than normal ATX PSU.... but that would give you more room to opitmize the design for whatever.

In fact, the PSU that Seasonic made for Arctic Cooling's Silentium T2 cases uses this very concept. The thing was hampered by less-than-great fans and too high a default min speed, but it seemed to be extremely well cooled.

Hello,

The AC Silentium T2 also has other "uphill battles":

1) the PS fans had to force the rising warm air back down through the PS
2) and the design of the fans (with their open frames) would seem to be poor when pushing against static pressure.

Air can too easily disperse to the sides if it cannot be pushed down into the PS.

But I think the basic idea of twin 80mm fans pulling air through the PS makes a lot of sense.

One misprint in the article, page 3:
"An secondary heatsink provides spot cooling for this transistor"

It is diode bridge rectifier, not transistor.

Good review Mike. Nice to see Seasonic finally going the modular route.

I'm starting to wonder if we need to hit people on the head with something heavy, before they start to understand that convection is a very weak force and absolutely no match for even the weakest fan.