Ladies and Gentlemen,

I'm on the prowl on the full rolls of wires that will support me for the future modding.

So, what size and gauges does PSU wires usess?

I only finds on frozencpu is 22AWG and 18AWG.

Help ?

Quote: Originally Posted by COMMODORE64 Ladies and Gentlemen, I'm on the prowl on the full rolls of wires that will support me for the future modding. So, what size and gauges does PSU wires usess? I only finds on frozencpu is 22AWG and 18AWG. Help ?

I'd like to say 18 gauge, I don't have a power supply to check. Most wire usually has the gauge and other information marked on the wire.

I would think that for a power supply you would want something more in the range of 8-12 gauge wire. 18-22 gauge wire is fine for going to small stuff like leds or fans, but I certainly wouldn't use anything that small for lines coming from the actual power supply. Remember lower gauge means thicker wire which means less resistance and that means that the wire can handle larger currents. If I am reading a chart I found right 22 gauge wire can handle 7 amps, 18 gauge wire can handle 16 amps, 12 gauge can handle 41 amps, and 8 gauge can handle 73 amps. The trade off is of course the size and flexibility of the wire, but you really do not want to overload a wire with too many amps (I have and it normally does not turn out too well).

Ok, you meant the bigger wire it is, the less resistance it gets and flows?

Quote: Originally Posted by COMMODORE64 Ok, you meant the bigger wire it is, the less resistance it gets and flows?

He means that, BUT wire gauge is inverse to wire diameter. SO the larger the wire diameter, the smaller the gauge and visa versa.

Quote: Originally Posted by COMMODORE64 Ok, you meant the bigger wire it is, the less resistance it gets and flows?

Yes, bigger wire (lower gauge) has less resistance which means you can have higher flow.

You really need to look at how much power you are going to be sending through the wires and pick a wire size that fits your need. A lot of older power supplies used 18 gauge wire but they were not putting out nearly as much power on those wires as they do on newer power supplies. It is not worth the hassle to use thick wires for small power requirements, so find out what your requirements are then choose a gauge that is appropriate to that need.

If you just want to buy a bunch of wire now so you can always have it around then you may want to buy wire of a couple different gauges such as 12 and 18. Doing that will give you wire to use for just about any task that you would want, at least within a computer.

EDIT:
boardboyd beat me to it a little bit there as well.

Well, you know some power supply has some ridiculous short wires, or don't organized enough.

So I want to try to get it out of way and do the cleaniest wires, such as one of those alienware do...

A clean straight wires connect each drives whatever it needs.

Is it a good idea?
Or should i leave it alone?

AWG ranges from 0 to 40, with 40 being the smallest and 0 being the largest in Diameter. The Smaller the AWG, The Less Resistance Per Foot the Wire Has, and the thicker it is. Smaller AWG also means more $$$. 18 AWG would be good for general PSU Wire.

Also, each AWG has a Current Limit for its size before it starts to heat up and losses are greater.

Quote: Originally Posted by COMMODORE64 Well, you know some power supply has some ridiculous short wires, or don't organized enough. So I want to try to get it out of way and do the cleaniest wires, such as one of those alienware do... A clean straight wires connect each drives whatever it needs. Is it a good idea? Or should i leave it alone?

Yeah I can understand. I would say that to connect your drives (hard drives and optical drives) and motherboard 18 gauge would probably be fine, assuming that you are not extending the wires to a really long length. For anything that could draw a very large amount of power, such as a video card, though I would suggest that you go for wire that is of a lower gauge. Also if you want to really extend the length of the wires then you might want to think about using lower gauge wires, especially on long straight sections, so that the distance does not cause too much of a drop.

True.

But i'm thinking about eliminate the extra Molex that I don't need, and replace it with a straight wire instead. Will that increase the resistance and heat?

I'm very concerned about the safety.

Quote: Originally Posted by COMMODORE64 True. But i'm thinking about eliminate the extra Molex that I don't need, and replace it with a straight wire instead. Will that increase the resistance and heat? I'm very concerned about the safety.

Eliminating extra connectors is just fine. Just keep in mind that if you are using a multi rail PSU that you will want to spread the load across all of the 12V lines so that none of them are overloaded. I would suggest that you draw out your plans for the wiring of the case and what lines will go to what components and add up the total draw for each line. Once you have that figured out then you can easily make a smart choice on what gauge of wire to use for each line. The only thing that I would worry about pulling too much power for an 18 gauge wire would be the video card and that is only if you are using a high end video card which pulls a lot of power.

Can you explain me little more about rail ?

Plus, how about modding a single or dual rail PSU ?

Give me some instruction please?

Quote: Originally Posted by COMMODORE64 Can you explain me little more about rail ? Plus, how about modding a single or dual rail PSU ? Give me some instruction please?

Quote: Originally Posted by PC Power & Cooling 8. ARE MULTIPLE 12-VOLT RAILS BETTER THAN A SINGLE 12-VOLT RAIL? With all the hype about multiple 12-volt rails (ads claim that two rails is better than one, five is better than four, etc.), you'd think it was a better design. Unfortunately, it's not! Here are the facts: A large, single 12-volt rail (without a 240VA limit) can transfer 100% of the 12-volt output from the PSU to the computer, while a multi-rail 12-volt design has distribution losses of up to 30% of the power supply's rating. Those losses occur because power literally gets "trapped" on under-utilized rails. For example, if the 12-volt rail that powers the CPU is rated for 17 amps and the CPU only uses 7A, the remaining 10A is unusable, since it is isolated from the rest of the system. Since the maximum current from any one 12-volt rail of a multiple-rail PSU is limited to 20 amps (240VA / 12 volts = 20 amps), PCs with high-performance components that draw over 20 amps from the same rail are subject to over-current shutdowns. With power requirements for multiple processors and graphics cards continuing to grow, the multiple-rail design, with its 240VA limit per rail, is basically obsolete. PC Power and Cooling is once again leading the industry. All of our power supplies now feature a large, single 12-volt rail. The design is favored by major processor and graphics companies, complies with EPS12V specs (the 240VA limit is not a requirement) and is approved by all major safety agencies such as UL and TUV.3

I think that should explain multi rail vs single rail a bit better than I can, even if it is basically an ad and somewhat biased. As far as modding one vs the other it really doesn't matter, mod what you have is what I would say. Just remember, no matter what type you choose to work with make sure that you will never be pulling more power through any wire then that wire is rated to be able to take (make sure it is the right gauge wire for the job). If you have any more questions feel free to keep asking them.

1. Now thanks for clearing this up. I will not purchasing the future multi-rails.

2. Thank you for clearing this up.

Some PSU's use 16awg from the wall, usually 700+ watt units. Most use 18awg. The internal wires aren't usually carrying such a high current and can use finer 20, 22awg. My coolermaster 850W(1000W peak) has a 14awg cord which seems like overkill, but makes me feel better.

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Quote: Originally Posted by Seyeklopz Some PSU's use 16awg from the wall, usually 700+ watt units. Most use 18awg. The internal wires aren't usually carrying such a high current and can use finer 20, 22awg. My coolermaster 850W(1000W peak) has a 14awg cord which seems like overkill, but makes me feel better.

The wattage really isn't the problem, it is the current ie amperage (watts are not equal to current, watts = current * voltage). A power supply does not pull that much current from the wall because it is pulling 110-220VAC. To pull 700 watts from 110V takes less than 7 amps, but the 12VDC lines inside a computer are very often carrying more than 7 amps and at times could be carrying up around 20-30 amps depending on what is connected to them. So comparing the wire to the wall and the internal wires is not a good idea. Also even the cheapest power supplies that I have seen, the ones that come with cases for free, use at least 18 gauge wiring coming from the PSU to power the components. I would recommend very highly against using 20 or 22 gauge wire for a PSU output.

Quote: Originally Posted by Snake2Snipe The wattage really isn't the problem, it is the current ie amperage (watts are not equal to current, watts = current * voltage). A power supply does not pull that much current from the wall because it is pulling 110-220VAC. To pull 700 watts from 110V takes less than 7 amps, but the 12VDC lines inside a computer are very often carrying more than 7 amps and at times could be carrying up around 20-30 amps depending on what is connected to them. So comparing the wire to the wall and the internal wires is not a good idea. Also even the cheapest power supplies that I have seen, the ones that come with cases for free, use at least 18 gauge wiring coming from the PSU to power the components. I would recommend very highly against using 20 or 22 gauge wire for a PSU output.

Thats not the reason [prepare yourself for a lengthy post].Skip to 2nd to last Paragraph if you dont want to read much.

Computer Power Supplies use Whats called a Offline Switch Mode Power Supply (offline meaning its runs from wall current-120V US, 240UK) Now, Mind you Power In= Power Out in a Perfect, 100% Efficient System. That means that you would be able to get 700W Out if you put 700W Into a Power Supply. But we live in a world were things arent perfect (but are getting better). Power Supply Efficiency Ranges from 80% to 95%, Which means at 80% you should be able to get around 80% of the Power you put into the system (ie, 80% of 700W Input). Ok, Thats settled.

SMPS Work By switching Inductors At a very high rate of speed (around 100Khz to 5 Mhz). By doing this allows for more efficiency and saves Space. Lets compare A SMPS to another type of Power Supply, The Linear Power Supply. A Linear power Supply is simple, A transformer is hooked up to a Bridge Rectifier and then to a capacitor Bridge and then to a external Regulator. But theres a problem associated with this type of power Supply, The Fact is, Power in Still Does = Power Out, But this is because of the way transformers Work. More Power Out means you need a greater capacitor to filter the output, and if you need multiple output voltages from one transformer, Forget about it. You'll end up with a power supply the size of a AC Unit. Not to mention it would cost about the same (or even more).

As I was saying before hand, inside a transformer Power In = Power Out. This is really true for all systems, But Since the transformer is an inductor, It can be switched at high speeds also, which leads to more efficiency,. How a transformer Acts depends on its turns ratio, it could either step up, or Step down a voltage. In Our Case a transformer Is Stepping down 120V AC To 12V (5,3.3..etc) DC. Seems Impossible Doesnt it? To step down Alternating current and at the same time Turn it into DC. Well its not, and its happening as I type. A PSU doesnt require a lot current not because its running from the wall, but because of a transformer. Naturally if you went to a lower voltage, you would need more current.

The First part of a SMPS is a just a EMI filter, Which prevents Any "bad" signals from flowing into your wall socket and harming other equipment, aka noise. After that, Is just a simple Rectifier with 2 Capacitors (the big huge ones). These Take 120V and filter it to 170 (or, in some cases, 340V Or so- This is what Active PFC does) After that, Its the main regulators Job to take that 170 DC or 340 DC and then step it down using a switching transformer. The transformer is easy to spot, its the square thing in between 2 heats sinks. the actually manner used to control the Voltage is a bit complex, but I can simplify it.

CPU's use Hz as a function of speed. So does everything else. Theres actually a small CPU inside your PSU that controls the Speed at which does the switching. A Coil Is chosen based on Input and Output (and many other things) as is a CPU. The CPU Varies The frequency Based On load and Feedback, If the output voltage goes too low, the frequency goes Higher, If its to high, the frequency decreases. Feedback just places an Voltage that tells the CPU to "stop sending a signal at this voltage"

I should also Mention this, Those who use 240V Actually get Higher Efficiency than those using 120V.

Well, I meant watts at 120 volts. I do understand watts, volts, current. The CM850 has 2 main transformers and 1 secondary. Pretty beefy.

Quote: Originally Posted by Snake2Snipe The wattage really isn't the problem, it is the current ie amperage (watts are not equal to current, watts = current * voltage). A power supply does not pull that much current from the wall because it is pulling 110-220VAC. To pull 700 watts from 110V takes less than 7 amps, but the 12VDC lines inside a computer are very often carrying more than 7 amps and at times could be carrying up around 20-30 amps depending on what is connected to them. So comparing the wire to the wall and the internal wires is not a good idea. Also even the cheapest power supplies that I have seen, the ones that come with cases for free, use at least 18 gauge wiring coming from the PSU to power the components. I would recommend very highly against using 20 or 22 gauge wire for a PSU output.

Quote: Originally Posted by Seyeklopz Well, I meant watts at 120 volts. I do understand watts, volts, current. The CM850 has 2 main transformers and 1 secondary. Pretty beefy.

Fair enough, it is hard to know who knows what online though so I was just putting the explanation out there. I was just saying that what matters with wires is the current going through them not the wattage or the voltage, at least in this case. At this point I will just say that I stand by my recommendations and I would refer anyone who would like to look at what amperages different gauge wires are rated to, to this page http://www.powerstream.com/Wire_Size.htm.