Single 30A or Dual 16A PSU?

[Aneesh@4GHz]

Hi,

Which is better psu?
One with single 30amp or one with dual 16 amp,Does the dual rail means it has 32 amps on 12v rail?

Thanks in advance!

 

[hunter315]

Depends more on the brand of the PSU. Dual 16 rarely means that it has 32A between the two rails, it will probably only have 30A between them still. Check the label on the PSU to see the combined power on the rails. Also check to see which one has a better warranty, as that tells you about the quality of the PSU. Most good ones come with a 5 year warranty, some come with up to 7.

 

[cjl]

Which specific PSUs are they?

 

[Aneesh@4GHz]

Corsair cx 400 has 30 amp on single rail
CM RS-400-PSAR-J3 400W has dual 16amps


wat bt this ,I think corsair makes solis and super psu ,I know that,But Its for my friend he did not need a costly psu,a cheap one but good so now he has a generic iball psu,Is the cm better than that he is goin to buy a 9600gt or some thing this month,So wats ur opinion?

 

[cjl]

Between those, I'd get the Corsair.

 

[Aneesh@4GHz]

Ya mee too like corsair,But his budget and also corsair 400 very costly here abt 5000RS,the retailersaid,Does it hold a dual core 2ghz 3gbram 9600gt and a 160gb hdd?


And also Dual 16 or single 30 ,Which is good,Is it safe to use a psu with dual 16amp?

 

[Aneesh@4GHz]

"Does it hold" The COOLER MASTER?

 

[hunter315]

Definitely the corsair, if you take a look at the picture of the sticker on the PSU it only has 23A(276W) between the two 12V rails, only ~70% efficient, and no PFC, the corsair is significantly more powerful, more efficient, and just plain better all around.

 

[Aneesh@4GHz]

What is PFC,I heared of it before Active PFC and somthing like that!

 

[Aneesh@4GHz]

sticker on the PSU it only has 23A(276W) between the two 12V rails

I think 32AMp,Not 23 amps!

 

[hunter315]

PFC is power factor correction, all newer models have active PFC as it allows them to be sold around the world since it can take any input voltage from 90V to 240V.

he power factor(PF) is the ratio of real power to complex power, ideally the PF should be 1 as that means that you are only drawing real power that gets used, active PFC keeps the PF around .99 while passive ones are generally significantly lower. The PF doesnt affect the end user very much but it greatly affects power companies as they must produce the total complex power even though you only need the real part of it. The PF can affect you though if you have a large item with a low PF on a circuit, if you are drawing 15A of real power on a circuit with a 20A breaker and your device only has a PF of .7 then you are actually drawing 21.4A of complex power which will trip the breaker. Anyway higher PF is good and part of any modern platform so always look for a PSU with APFC.

For more about PFCs and PF take a look at the FAQ over at jonnyguru
http://www.jonnyguru.com/forums/showthread.php?t=3988


No it really is only 23 unfortunately, go to the newegg page and look at the pictures, find the one of the sticker and you will see that the combined power is 276W, 276W/12V=23A
http://www.newegg.com/Product/Product.aspx?Item=N82E16817171042

 

[Aneesh@4GHz]

ok,Thanks hunter315,I will ask my friend abt this and will come back later

But replies & suggestions are invited

 

[cjl]

That CM is a pretty mediocre PSU. No active PFC and only 70% efficient. I'd definitely get the Corsair.

 

[cjl]

PFC is power factor correction, all newer models have active PFC as it allows them to be sold around the world since it can take any input voltage from 90V to 240V.

he power factor(PF) is the ratio of real power to complex power, ideally the PF should be 1 as that means that you are only drawing real power that gets used, active PFC keeps the PF around .99 while passive ones are generally significantly lower. The PF doesnt affect the end user very much but it greatly affects power companies as they must produce the total complex power even though you only need the real part of it. The PF can affect you though if you have a large item with a low PF on a circuit, if you are drawing 15A of real power on a circuit with a 20A breaker and your device only has a PF of .7 then you are actually drawing 21.4A of complex power which will trip the breaker. Anyway higher PF is good and part of any modern platform so always look for a PSU with APFC.

Although this explanation is pretty good, I have one minor nitpick (sorry). Amps aren't power. A device drawing 1200W of power with a PF of 1 on a standard 120V circuit will draw 10 (real) amps, while with a power factor of 0.5, it will draw 20 (real) amps. The additional amps are quite real - the power itself is what is "apparent" or "imaginary" due to the phase angle between the voltage and current.

 

[jsc]

... the power itself is what is "apparent" or "imaginary" ...

What?

I'm kidding.

But seriously, power factor, PFC, and APFC really aren't topics for (I don't want to sound condescending) the technically illiterate. But trust us. APFC is a good thing. It's not just an advertising feature. In fact, I don't think you can sell a PSU without it in Europe now.

 

[cjl]

I believe you are right. 80+ requires a PF of 0.9 or better as well.