Single or Two Rail

H

heydockyle

New Member
Setup is this.

ASUS M4A785-M
AMD Phenom II X2 555
1 Sata Harddrive, will upgrade to a new 1tb sata later on.
And probably two dvd drives.

Later on I will add another graphics card, and try to use Hybrid CrossFireX but nothing too power consuming.

I can get this http://www.newegg.com/Product/Product.aspx?Item=N82E16817341017 for $50.
Description says its A four rail configuration balances the power output for consistent performance.
In the specs it only lists 12v1 and 12v2...

Isn't that two rail?

I was looking at this also. http://www.newegg.com/Product/Product.aspx?Item=N82E16817139008&Tpk=corsair 400w


I figure If I'm going to spend 45 on 400w I might aswell spend 50 on 600w, but would the 2 rail be a downfall on my system?

Thanks
 
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The ocz psu that you are looking at looks like a good deal. I am not sure about how the calculation works for amps (you can't just add the rails together) but the corsair with a single rail at 30a on the 12v rail vs the ocz which has two 12v rails with 25a on each rail. The ocz will have a better sustainable power and has 2 6pin pci express connectors for your graphics cards. If you want to crossfire later, get the ocz. 400W will not be enough.

by the way, I have no idea why it says 4 rail configuration. The specs say dual rail. I would trust that.

The debate over single rail or multi-rail is about wasted power vs. stability. A lot of power on one rail can be more unstable or can have worse failures ie. blowing out your system with a surge. On a multi-rail system you have maxes for each rail and people say that you have wasted power that is trapped on a rail dedicated to a certain component while others need more power. But splitting up the power can make it more stable.

Either way you go, you get what you pay for. Any psu can be faulty and unstable. Make sure that you get one from a good company. Don't skimp on the power supply!
 
salvage-this said:
The ocz psu that you are looking at looks like a good deal. I am not sure about how the calculation works for amps (you can't just add the rails together) but the corsair with a single rail at 30a on the 12v rail vs the ocz which has two 12v rails with 25a on each rail. The ocz will have a better sustainable power and has 2 6pin pci express connectors for your graphics cards. If you want to crossfire later, get the ocz. 400W will not be enough.
Click to expand...

To clear that up: Each rails has a maximum current it can provide, whether it's single or multiple rails. So a single rail system usually has a large maximum current draw, while multiple rails have a smaller maximum current draw on each rail. You just need to be carefull not to overload a single rail. For multi rail PSU, this means making sure you don't draw to much on just one rail.
salvage-this said:
[...]
The debate over single rail or multi-rail is about wasted power vs. stability. A lot of power on one rail can be more unstable or can have worse failures ie. blowing out your system with a surge. On a multi-rail system you have maxes for each rail and people say that you have wasted power that is trapped on a rail dedicated to a certain component while others need more power. But splitting up the power can make it more stable.
Click to expand...

About that "trapped" power, when people are saying wasted power, what they really mean is that there a bit of more power available on a rail, but you can't use it without drawing to much power.

For example let's say you have three components to power, each draws 5 amps. And let's say you have 3 rails that can provide 8 amps each. You have 16 amps available with just two rails, however, putting two components on one rail will draw to much current for that one rail. You have no choice but to place three components on three rails.
 
Okay, so when I get this psu should I split things up between the two rails?

Going to have 1 hd, 1 dvdrom, and then the mobo and processor stated above.
 
Personal preference single rail. That way I know exactly my amps/power and I am 100% sure it can power what I buy.

Its a simplicity thing with me :P
 
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