A PSU Problem

dose it matter what volatage or ampage it is what aslong as it has enough watts?

and it matter if the ampage is slihtly over on the 12V rail and i dont understand someone said a single rail is better is this true?

definity said:

and it matter if the ampage is slihtly over on the 12V rail and i dont understand someone said a single rail is better is this true?

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single rail is better if its got alot of amps and most of the time amps on the 12v rail matter more than the max wattage of the psu

Getting enough amps on the 12v (around 35 in most cases) is much more important than just a high amount of watts. What do you mean by "and it matter if the ampage is slihtly over on the 12V rail"?

Single rail psu's can be more reliable than dual rail psu's in some cases in making sure your 12v amps are best used or used at all. If you have 12v1@18 and 12v2@18 and your 12v for cpu requires more than 18a you could be out of luck even though you got an extra 18 on the other rail. One of the forum stickies links to a good article about psu's and how the 12v amps works. http://www.silentpcreview.com/article28-page3.html although it doesn't seem to be working right now.

If your looking for a new psu for your sytem post them here and somebody can give you an opinion on it/them.

hmm ok thanks but i need a +12V for the hd 1 and 2 and for cd burners and and for my graphics card aswell so dose this mean i cant have a single rail PSU, and i meant if the ampage is slightly over say 35 amps is required but its 38 amps would that blow stuff up?

Wattage is not that important. You need to see how the power is distributed on the PSU. With modern systems, the 12v rail is very important. (What you need of course depends of what your system is made)


Are you looking for a new PSU? If so, post your system components and we can help to recommend you the appropriate PSU

definity said:

hmm ok thanks but i need a +12V for the hd 1 and 2 and for cd burners and and for my graphics card aswell so dose this mean i cant have a single rail PSU, and i meant if the ampage is slightly over say 35 amps is required but its 38 amps would that blow stuff up?

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Hard drives and optical drives like cd burners rely on the 5v not the 12v. You don't need to worry about these components as modern power supplies have plenty of amps available for these devices. The 12v is used for cpu's and you graphics card which require much more power.

You don't need separate rails for each component. A single 12v rail can power your system easily with enough amps.

38a will not hurt your system if 35a is required. Actually just the opposite. 35 is a minimum for your system and it is a good idea to have a psu with more than needed so your system is not maxed to the point of instability. The extra amps will not hurt your system.

Just dont leak your amps. things get bad in a hurry if you do. especially if they touch you, or metal.

ohms law

I have a ultra X connect 500w that has 34a on the 12v+ and I tried a antec true power trio which has 3 12v+ rails of 18a each and I found that the ultra X connect gives me readouts in the bios that are closer to where they should be. Aside from that I didn't do any other forms of testing so I can't really say which is better. All it means is that the ultra x connect was putting out higher voltage but the antec was probably offering a much more stable current. The rails were so low on the antec though it was sad.

The rails always read high on the ultra - x connect for me even under heavy loads, I never see the +5 go under 4.95, the +12v go under 12.15, or the 3 go under 3.3v. With a multimeter I could probably better make a determination (or some other tools). I think when your rails readout pretty low though thats not a good thing, and the single rail PSU has so far given me better readouts at idle and at load, actually my load readouts on the ultra X were better than the antec 650's idle.