They have an HX520 as well.

At Newegg, HX520 is $129.99, Seasonic M12 500 is $139.99. Pretty much the same deal. I found one thing off, the Corsair reports three 12V rails @ 40A while the Seasonic reports four @ 38A. Kind of odd.

Seasonic's sticker for the 500W shows 38A total on the 12V circuit = 456W, while the Corsair shows 480W over the 12V range, which is 40A. The Corsair has a slightly higher rating (520W) so I suppose that's where the extra watts come from, but it's odd that they're claiming more rails on the lesser-rated supply. After reading jonnyGURU's page about the M12, it seems even more silly, as they're pretty much lying about the multiple rails anyway. For those that didn't read, Seasonic removed the multiple rails due to high-end video cards overloading the 18A allocated to their rail. Not necessarily a bad thing, but it'd be nice if they weren't being slightly deceptive about it. Power-wise, it'll still deliver whatever you need, but, as jonny points out, you lose some of the goodness of multi-rail.

So... could that be a problem with SPCR's sample?

I am hoping to see a review of the Corsair HX520 here since spcr seems to be on a roll with all the PSU reviews as of late.

coming...

Superb! I'm looking forward to it, keep up your magnificent PSU-work.

AtW

Hi there! I have been reading your great reviews since yesterday and I am wondering how silent a M12-500W power supply would be at around 250-300W real load (not AC).

I am searching for an ultra low noise power supply in order to exchange my noisy Enermax Liberty 500W. The new supply will have to feed 130W real load + a new G80 graphic card. I think they will eat up to 160W real power. So my new power supply should be able to feed my computer with 250-300W, without spinning up its fan (except for hot days in summer, when its unavoidable).

Which supply would you recommend? After having read and after having compared a lot, I think either a S12 550W Energy Plus or a M12 600W would be best to fit into my expectations.


And yes, sorry for all my mistakes, as you can see, I am not a native speeker, so please excuse my lack of knowledge.

The S12 Energy Plus or M12 are probably your best bets with that high of power consumption. If you look at the table on Page 4 of the Seasonic S12 Energy Plus review, they show a comparison of noise levels of some of the most quiet PSUs. The S12 E+ and M12 don't even begin to spin up until over 200W, probably closer to 250W and are still pretty quiet even at 300W. Much better than any other PSUs at that load.

interesting read, but the review didn't really harden my decision to go for the m12 700. i like the idea of a modular psu, but i'm not so keen about it that i'd tolerate any disadvantage for that.

i'm about to buy an average gaming rig (E6600, 2gb ram, one 7900gtx or 8800 gts, one seagate hdd, zalman reserator 2) but i'll probably use the second sli slot later to put a second gpu in there once the latest games don't run fluently anymore and of course i'd like to keep the psu then.

are there any major drawbacks if i choose s12 650 over the M12 700? do these 50W really make a difference concerning the possible max setup with two 8800 gts cards?

as the initial setup will only contain one gpu and the water cooling system has it's own power supply i think i'll be on the sunny and non-buzzing side with the S12, right?

ps: did seasonic promise to give you some feedback on the buzzing problem once they've started investigating?

...

If any, its an improvement from the specs.

I got my 550W E+ today and I am not fully satisfied with it. First, it is of course less noisy than my old Enermax. But it has a light, high frequency sound. It is only noticable when you are about 40cm close to the PSU and it isn't audible all the time, but it exists.

I would like to know if you have noticed such a sound aswell and if I have to care or not.

[/rant on]
Whats good about multi rails? from what i've read, the ONLY reason psu makers switched to multiple 12v rails was because some dumbass that was writing the specifications for PSU's decided it was too dangerous to have more than 18a on a single line. Which it isnt.

Multi Rails is hyped up bull****, pure and simple. Some guy in a suite was worried about lawsuits so he made it overly safer than it ever needed to be.
[/rant off]
--------------------------------------------------------------------------------

I like the M12. The 60mm fans is a bit of a sore spot, but from what everyone is saying, by the time it ever turns on the rest of the system is already so loud you wont even notice, and most of us at SPCR would never put a load anywhere close to it turning on even with the 500w model. So its really not an issue at all.

I would like to see an SFX M12 on the retail channel. 300watts, 80plus certified, modular cables.



The last page of the review has it broken down by DC and AC power. The listed SPL for 40w DC through 250w DC is the same. 21dbA.

EN-60950 safety requirements: power above 240 VA on user-accessible rails may lead to additional risk of fire in case of short-circuit or other failure. 240 VA / 12 V = 20 A max.

But there's almost no PSUs with real multiple rails because it's simply unnecessary. Almost all PSUs have one 12 V rail inside and several shunt resistors between this rail and external connectors. If current through one of it exceed 18 A, PSU shuts down. So multiple rails doesn't affect power or stability in any way.

Don't know if I have a newer version or something but my 60mm fan stopped after a couple of minutes after the load had dropped.