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Discussion Starter #1
I am really confused. Which is better. One 12 volt rail or 2 12 volt rails. Why?
I thought the more rails the better. Also, do you not just add up the total amps on all the rails? (2 12 volt rails @ 18 amps = 36 amps?)

I wanted 30 + amps for my computer. I will run a 7600 Gt video card, 320 sata 3.0 hard drive, dvd burner, and that is about it.

jake
 

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You add up all the amps for the 12 volt rails e.g. two 18 amps = 36 amps total, and even 4 rails is better. But you also need to consider the efficiency and quality of the PSU you are getting. A cheap PSU that claims high wattage often runs hot, is inefficient and the voltage fluctuates considerably on the rails - which is BAD.

You are better off spending some money on the PSU and making sure you get a good one. It's one of your longer term investments for your rig - since it usually is not replaced as often and can outlast most of your other components. Seasonic puts out good PSU's and they are quiet. There is an excellent 4 rail PSU on the market right now by GameXStream? FSP group looks good too.
 

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Dual 12V rails will provide dedicated power to resource-hungry components (PCI-E VGA), just make sure that there are at least 18A (amps) on the rails, 20A is better.

Some PSU's have triple 12V rails! But 2 ought to do ya for your setup.

The math you have is correct, but add the components (Fans, Controllers, Optical Drives, HDD, etc...

I'll try to find a calculator for you.

Here ya go: http://www.extreme.outervision.com/psucalculator.jsp
 

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Discussion Starter #4
Thanks, I thought you add up the amps. I also heard it was more stable. I was looking to spend around 60 or 70 bucks. Would that be enough?

Thanks again
jake
 

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Discussion Starter #5
ANOTHER QUESTION....

I was looking at 2 simualr products. They both claim to be 18 amps on 2 12 volt rails. However, on says it is around 50 amps on the 5 volt rail, the other says it is around 30 amps on the same 5 volt rail.

Is one of the brands lying about amps? It sounds fishy to be pumping so much (50 amps) on the 5 volt rail and still claim 18 amps on 2 12 volt rails.

Am I clear? I hope so...
Jake
 

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$60 or $70 may be a little low if you want a good gaming rig and want to overclock. If you're planning to SLI or Crossfire your GPU's for the future and run RAIDs for your HDDs, you will probably want at least a 600W rated PSU and getting a good one will probably put you at least over $100.
 

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Discussion Starter #7
THanks Jamenta
I will do some gaming but will limit to just one card. My computer really is kind of bare. Plus, my motherboard limits me to just one video card ( I knew i would never need two vidoe cards). SO would 60 ot 70 do for that?

Jake
 

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For lower price solid PSU you might check out ANTEC's line. Visit newegg. Newegg always has competitive prices. Here's a link to an ANTEC on sale now... but again if you're planning to game, you may want to get a higher wattage brand:

http://www.newegg.com/Product/Produc...82E16817103937
 

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Discussion Starter #9
Thanks again for the link. I really do not know what "brand" is good. I am kind of glad that there are no fancy lights. I could care less if it had them. For some reason, I think it is sketchy to have the fancy lights at my price range
 

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Discussion Starter #12
What is the advantage? Would i never get the full amps (36) on 2 rails becase the 2 rails are really for balancing?

I am open to one rail or more. I just want the most power for the price.
Jake
 

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Forton (FPS), SilverStone, PC Power (prices will scare you), and Antec are fine products among others.
Single rail, or multiple rail, in the EU no rail is allowed to excede the 20a level, that is there, not here. Either way you cut it your using 1 vid card and unless you have a ton of other extra stuff the high 20a will do the job but a stronger PS will provide more cleaner stable power.
Look for things like an "Active PFC" and overvoltage protection too!
A few PS that will do the job well provided you don't have a ton of extra periphials. Had you posted your "System Specs" via the USER CP we would know more about your system

A few very good ones IMHO
http://www.newegg.com/Product/Produc...82E16817104022
http://www.newegg.com/Product/Produc...82E16817163112

A supplyer that has been around for many years.
http://www.newegg.com/Product/Produc...82E16817174024

Just a few examples, there are a ton more that generally are SLI certed.
 

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Discussion Starter #14
The Duke

You said "...in the EU no rail is allowed to excede the 20a level, that is there, not here..."

What do you mean it can not excede the 20 amps level?

Jake
 

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EU uses the 230v standard where as the US uses the 115v which may be the reason for that over there... not sure. Each has there standards.
 

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Quote:


Originally Posted by HrnyGoat

The PC Power&Cooling Silencer series have a huge 12V rail, with the 700W model having a 60A 12V rail. Id honestly prefer that over mulitiple 12V rails, since you dont have to worry about balancing out the loads.

Damn right!
I don't use and will never use a multiple rails PSU.

loganharpdawg; If that's all your going to be running w/o no future upgrade, I'd say get the OCZ PowerStream OCZ520ADJSLI ATX, BTX, EPS12V 520W Power Supply FOR $99.99 AMIR. That PSU has a 33A in the 12V rail, I got one and it's a very reliable PSU.
 

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Discussion Starter #17
Nasgul, What is the big deal about you not liking more than one rail? Is there something that I need to know?

Maybe I do not understand how these PSU's work. Is one rail used only for one thing and the other rail only used for something esle? Or do both rails combine amps and the amps are used whereever needed?
Jake
 

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First: you do NOT add up the 12V rails. Example: The Sunbeam NUUO (a popular PSU on this forum) delivers 20A on 12V1 and 18A on 12V2. However, as you can see on the image below, the total Max Output on the 12V rails combined is only 30A (35A peak, but who cares about that)


I have several FAQs about PSU and rails. Read them.
Do you need multiple 12V rails?
How much current (Amperes) on 12V rails?
PSU - Modular or not

It all depends on whether a PSU is built well.. There are excellent single 12V rail PSUs (like the PC Power & Cooling mentioned before, and there is also the SILVERSTONE SST-ST56ZF 560Watt which is an excellent choice if the PC Power & Cooling it too expensive. Indeed, the advantage is no worries about balancing the loads.

Also, there are more than excellent multiple rail PSUs. Right now, in that category, the OCZ GameXStream/FSP Epsilon are among the best (these two series are identical, built by FSP). Other good ones are the Enermax Liberty, Seasonic S12, and several others.

Go for good quality, and then it does not matter a whole lot how many rails there are.

Best bang for the buck in my opinion:
PC Power & Cooling Silencer 610 EPS12V EPS12V 610W Continuous @ 40°C Power Supply - $159.99 + free shipping.
 

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Discussion Starter #19
CHOZART
Wholy Crap! This is exactly what i was looking for. Thanks for the great info. I knew there were some tricks about finding out what the "real" power actually is on PSU's. Thanks again for the info.

Jake
 

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Many CPUs have an image of that label listing their max load on the 12V rails combined. Some in Amperes (like this NUUO) and some in Watts (NUUO actually both). If you see only Watts, divide by 12 (it's 12V) to get the amps. (for the NUUO, 360/12 = 30A).

Some PSUs (notably the GameSTream and the Epsilon) lack this detailed information. Just for your info, the 600W GameXStream/Epsilon delivers 44A (quad 18A rails) while the 700W version delivers 50A (also quad 18A rails).
 
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