BleepingComputer.com: doubts

Hi

I wish to know about the +12v rail,multiple 12v rail.

I have built a basic home PC around INR Rs26,000.

I saw the config. in a magazine.
And used a few youtube videos mainly to understand which PSU cable goes where.


What I wanna know is about the +12v rail

All I know is that it powers the motherboard and graphics card mainly.

I have referred wiki pages but can some one explain to me about the amps and other factors.


In simple language.

thanks in advance

You are correct, the +12v rails supply most of the power to your components such as your CPU and Video card. Basically, they take the voltage and turns them into amps. Different manufacturers use different methods, most of your low end PSUs use a single +12v rail, usually rated at 18 amps or less, and wont power a lot-for any kind of gaming rig, theyre practically worthless. In the mid to high range PSUs, theres two different styles-some manufacturs again, use a single +12v rail rated at anywhere from 40 amps on up. Others, divvy up the amperage between multiple rails-anywhere between 2 to 6 +12v rails. For example, my PSU has 4 +12v rails at 19 amps each. When your building a gaming rig, with a single mid to high range video card, you want a PSU with at least 40 amps on the +12v rails, if its a single +12v rail then you need 40 amps on it, if its multiple, then you add up the combined total. For example, my power supply with 19 amps on each of the 4 rails, has a combined total of 76 amps total. As you can see in my signature, Im running a crossfire setup with dual hard drives and a quad core CPU-which is why I have a PSU thats rated that high.

Its good your asking this question-a lot of people just assume that because a PSU has the "recomended wattage" that it will run the video card they want, and its often not the case, especially with low end Power supply units. Ive seen 6-700 watt PSUs with only 15-17 amps on the +12v rail, and that just plain wont cut it, and another thing to keep an eye on, with low end PSUs, that wattage is the peak power, as in if you hit that power, it will likely fry within a minute of running it. So a 600 watt low end PSU, will likely only run at maybe 500-520 continuous, depending how efficient it is, if you hit that 600 watt mark continuously you will fry the PSU. Your high end PSUs, they advertise their continous power, which means a quality 650 watt PSU will run at 650 watts continously. Just something to keep in mind.

Things to look for in a PSU for a gaming PSU:
At least 550-600 watts continous power for a single video card, 750+ for multiple cards (depending on the card and how many)

At least 40 amps total over the +12v rails for a single card, 60-70+ for multiple cards, especially high end ones. (what I would recomend anyway)

At least a 80% efficiency rating, if not higher.

Most quality PSUs the cables are wrapped for better cooling, getting a modular PSU is nice, but also pricey. If you cant afford a modular, its not needed, as long as your wattage, amperage and efficiency rating meet your requirements you dont necessarily need it.

Rule of thumb when building any computer, Never skimp on the PSU or the Motherboard, theyre the backbone of your computer. If your motherboard goes bad, it can be a pain to replace, and if your PSU goes out it runs a risk of damaging other components in your computer. If you have any more questions, or need something explained better, feel free to ask. I included some basic defintions in the links below to help.

amperage: http://en.wikipedia.org/wiki/Amperage

Voltage: http://en.wikipedia.org/wiki/Voltage

Power rails in a power supply: http://en.wikipedia.org/wiki/Power_supply_rail

Thanks a Lot

This post has been edited by midou1994: 17 June 2011 - 11:04 PM

The +12v rail is connector right as they say 20/24 pin.


Also regarding type of PSu

My understanding is

Modular the cable can attached and removed and in Non modular it can`t be done.


any more things I should know off.


Also is the information regarding rail given in the Manufacturers website

UPDATE:

Saw Corsair website +12v rail 40 amps

so,I guess thats the rail and 80 plus certified is the efficiency rating?


Japanese Capacitors?

This post has been edited by midou1994: 18 June 2011 - 12:31 AM

Correct on all accounts, modular allows the cables to be removed as necessary. Its a nice feature, especially in a tight case, but as long as theyre wrapped modular's not needed. And corsair is a reputable brand, I trust them. What kind of system are you putting it into and what specific psu just out of curiosity?

Which Corsair power supply?

hi


Actually am not putting but thinking about my existing one


I used the config in magazine,


As i mentioned earlier
it comes with a PSU

the case is from iball so is the PSU

250 watts
But does the job for browsing and other stuff..



hi Killerx

Just looked at the spec to see the amps on the 12 volt
tats all no specific Power supply

This post has been edited by midou1994: 18 June 2011 - 02:04 AM

For finding the +12v rating on your current PSU, its often found on the PSU itself, there should be a sticker on the side with a series of small boxes with numbers with them. With that low of a PSU (250 watts) theres likely only 1 +12v rail, so you will see a box that says "+12v" and directly below that box there will be another box with another number followed by an "a" for example, "12a" that number is how many amps is on your +12v rail.

Thanks


Would you recommend increasing the PSU to 400-500 watts?

Depends what your doing with it. If its running your current system fine, and your not planning on upgrading, then I see no reason to upgrade the PSU. If your wanting to say, upgrade the video card or something like that then a PSU upgrade might be worth it.

ok.

If you have a good 250W psu like my spare ChannelWell one, it could power up a low end graphics card like the one i have in my brothers system which is a ATI X1650 Pro.

a low end grpahics card ??

Hmm Will check out and see if i wish to make a few changes


and if the budget fits the lappy already eats up some cash

It really all depends on what you use it for.

Hi again I need some advice regrading upgrade should I start a new post system building and upgrading or continue here??