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Seasonic M12 SS-7004: Does this have 4 -12v rails??

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Last response: in Components
November 22, 2006 8:26:10 PM

I am thinking about ordering the following PSU

http://www.newegg.com/Product/Product.asp?Item=N82E1681...
It is a seasonic M12 SS-700HM ATX 700W

My question is "does this have 4 - 12v rails or does it have 2 rails with each split into two?"

I was also thinking about getting the Antec True Power Trio TPS-650.
This says it has 3 rails, but we had a forum comment that this PSU is also a "split rail" PSU not a "true" 3 - rail PSU??

Thanks

Grant

More about : seasonic m12 7004 12v rails

Anonymous
a b ) Power supply
November 22, 2006 9:51:21 PM

It is somewhat obscure, It is apparently on huge rail.
Excellent review

Quote:
asked Seasonic about this "descrepency" and it was stated that the "deception" is really quite innocent. Apparently the initial design was for quad rails, and if rails did need to be split up into three or four rails, it would be easy to implement without completely redesigning the platform. Multiple rails can be split up with a separate OCP circuit board, typically screwed to the top of a heatsink.

What Seasonic tells me is that there was an issue with high end video cards overloading a single 12V rail. So with Intel's blessing, Seasonic removed the OCP. Technically, Intel has removed the 240VA rail limit from the ATX12V specfication (although I've yet to see this published on FormFactors.org), and the UL simply considers devices with single output leads with output capability greater than 240VA (12V @ 20A) a different product class (level 6 instead of level 3.)

Although I have little issue with a single 12V rail as it does allow almost any load to be put on almost any connection, I do wish a correction to the label was done. Single 12V rails work well for high end machines with video cards with GPU's that can easily overload your typical rail, but you do miss the advantages of split 12V rails, such as separation of "noise" between rails and the protection provided by the separation so a potential short on one rail doesn't harm a device loation on another.


Superb PSU, what I am getting...[/code]
November 23, 2006 2:47:48 AM

Hi Labbbby

Thanks for the 'quote' and the link to this review on the SeaSonic M12 SS-700HM. this is a very positive review.

That review also mentioned the Cosair HX 620.
The Cosair has 3 12v rails and these rails are really separate.

I read the review on the Cosair and it is also really positive and is the highest rated PSU by Legit Reviews

http://forums.legitreviews.com/about6227.html


So, which is better the single rail with 4 splits (SeaSonic M12) or the 3 separate rails (Corsair HX 620)??

Thanks

Grant
Related resources
November 23, 2006 3:01:49 AM

Hi Verndewd

The system I am building is as follows:

NVIDIA 8800GTS Video eVGA
680i Mobo Asus or eVGA
Cosair 2gigs XMS2 DDR2 800 C4
E6600
3 @ Seagate 7200.10 320GB
2 DVDs
TV Tuner

So I really don't need all that power, but I want to be on the super safe side

Grant
November 23, 2006 5:56:49 AM

To quote a quote:
Quote:
Although I have little issue with a single 12V rail as it does allow almost any load to be put on almost any connection, I do wish a correction to the label was done. Single 12V rails work well for high end machines with video cards with GPU's that can easily overload your typical rail, but you do miss the advantages of split 12V rails, such as separation of "noise" between rails and the protection provided by the separation so a potential short on one rail doesn't harm a device loation on another.

Which is precisely why NVIDIA chose to to use (2) PCI-E connections per card when they designed the 8800 series.
November 23, 2006 6:56:49 AM

Read:

http://www.xbitlabs.com/articles/other/display/atx-psu6...
http://www.xbitlabs.com/articles/other/display/atx-psu5...

The <high number of> rails is a misconception.
Of course you (may) still want as many cables as you can get, and have decent wattage on a quantity of 12 V lines - eg: for Quad-SLi GeForce 8800 GTX (if it is even possible... yet).

These are the recommended (certified) PSUs from nVidia / ATI:

http://users.on.net/~darkpeace/psu/List_of_Recommended_...
http://ati.amd.com/technology/crossfire/buildyourown2.h...
November 23, 2006 12:09:43 PM

Hi Tabris..

Wow!

Thanks for all of the info.
Have to study this some more??

Grant
November 25, 2006 12:59:44 PM

Hi All

Well I decided that what I WANT is the Seasonic M12 700W. I chose this PSU because it is has modular cables and certified by NVIDIA to handle two 8800GTS cards.

I also really like the Corsair 620HX. It is also modular but it is NOT certified for a dual 8800 GTS system.

I find that odd because the Corsair has 3 independent 12v rails @ 18 amps. This should be able to handle that system.

Maybe the Cosair it is not certified because it has a independent rail setup and it does not have the ability to go beyond 18amps on each rail if needed. Edit, I just read in the Cosair brochure that it has an "Advanced circutry design that automatically enables sharing between the triple 12 v rails in an event of overload on any single +12v rail" ??

Also, the Antec TruePower Trio 650W has "3-rails that are shared" and it IS Certified for a dual 8800 GTS system. The Antec is similar to the Corsair in that they both have 3- 12v rails and really similar power chracteristics??

The Seasonic has "4 12v leads" that are really two independent rails each split giving 4 rails total. So it can use more than 18 amps on each these rail pairs up to a combined limit.


Now the problem is that I cannot find the Seasonic M12 700W anywhere on the web :( 

Suggestions please??

Grant
November 26, 2006 7:54:03 AM

Hi there,

Man after my own heart, I am also going for the Seasonic and have found two stockists

Overclockers

And
Chillblast

Both have it in stock and both at £124.99
November 26, 2006 12:23:02 PM

Hi Archaic

Thanks for the info on the Seasonic M12 700W
146 british pounds is equal to 281 US$

I ordered the Corsair HZ 620W for 160 US$.
The Corsair is a very robust PSU that will meet my needs well

Thanks

Grant
November 26, 2006 2:48:58 PM

No worries


I am sure that they are both very good for the purpose :) 


Good luck with the build