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+12 Volt Amp Rail Confusion

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February 5, 2009 5:03:38 AM

Ok so I am very confused on what power supply to buy. So heres my question I am looking at this http://www.newegg.com/Product/Product.aspx?Item=N82E168... ...... I know I know its a cheap-o and it might not work but there also is that chance that it will and I just got done forking out almost the last of my savings. So it has 4 +12 volt rails at 19amps a piece so would that be equal to 76amps??..

Ok for the second part of my question would this power supply if in fact a get a good one run this pc.
Processor= http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Mobo= http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Ram= http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Video card= http://www.newegg.com/Product/Product.aspx?Item=N82E168...
+2 7200rpm hdds +8 fans + 1 dvd drive + a few other pci things
Also Iv been reading the negative reviews and there are 2 of them with i7 processors so I am a might scared there but im hoping I will get a good one.

Iv already used the power supply calulator but I just want to get a second option.

Thanks for your time
Cody
a c 87 ) Power supply
February 5, 2009 5:13:18 AM

Hec is not a brand I'm very familiar with. I think they are ok, don't stress of buying this. It should be strong enough to handle the GTX280.
a c 87 ) Power supply
February 5, 2009 5:16:12 AM

Forgot to mention, no, it doesn't have 76A on the 12V rail. Each rail might be capable of providing 19A, but the thing that feeds those rails is probably capable of something else. If you look at the white picture, all four 12V rails sum up to 720W. 720W / 12V = 60A. The PSU is able to provide 60A, each rail can have a max of 19A at a time.
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February 5, 2009 5:23:04 AM

So if the video card itself requires 50amps then + everything on my computer it still should work?
a b ) Power supply
February 5, 2009 6:07:21 AM

codywolf16 said:
Ok so I am very confused on what power supply to buy. So heres my question I am looking at this http://www.newegg.com/Product/Product.aspx?Item=N82E168... ...... I know I know its a cheap-o and it might not work but there also is that chance that it will and I just got done forking out almost the last of my savings. So it has 4 +12 volt rails at 19amps a piece so would that be equal to 76amps??..

Ok for the second part of my question would this power supply if in fact a get a good one run this pc.
Processor= http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Mobo= http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Ram= http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Video card= http://www.newegg.com/Product/Product.aspx?Item=N82E168...
+2 7200rpm hdds +8 fans + 1 dvd drive + a few other pci things
Also Iv been reading the negative reviews and there are 2 of them with i7 processors so I am a might scared there but im hoping I will get a good one.

Iv already used the power supply calulator but I just want to get a second option.

Thanks for your time
Cody


HEC is not a good brand. Good choices are PC Power & Cooling Silencer 500W or Corsair VX550.

12V rails are almost never additive, as mentioned above.

Power supply calculators overestimate because of low quality PSUs.
February 5, 2009 6:38:18 AM

A good quality 650w would be a better choice.
February 5, 2009 7:11:50 AM

Thanks for the info everone ended up buying the one I was thinking about. If it doesn't work I can always RMA back to newegg THANKS!.
a c 87 ) Power supply
February 5, 2009 7:41:17 AM

First, no single video card uses 50A. Two GTX280s and the rest of the system might could probably do it, but not many other cards can. 30A is fine for a single card, 45A is fine for most dual setups.

Second, I would have bought monkey's second PSU. (the trio is an older design, not so good anymore.) You can't go wrong with SeaSonic, and as mentioned its cheaper to.
a b ) Power supply
February 5, 2009 7:55:02 AM

codywolf16 said:
Thanks for the info everone ended up buying the one I was thinking about. If it doesn't work I can always RMA back to newegg THANKS!.


The thing is with lower quality psu's is that they will work, but, and this is the big but, they will work for a while and then they will die, sometimes taking the rest of your system with it, they will degrade over time a lot quicker than a good quality psu. The other mode of failure is a not so regulated supply, especially near full load, in which case you'll be seeing system instability, be prepared to lose hdd content if raiding (either 0 or 1), be prepared to see random crashes, be prepared to not be able to pin down the problem to a single component, I doubt you'll be able to prove that the psu is 'at fault', they may rma it anyway, but be prepared to run your pc with your fingers crossed.

The psu is the foundation of a pc, if its bad the pc is bad.

I don't understand why you went with the cheap POS PSU and not a much much better one at the same price (I could kind of understand if there was a pric difference), well its the last of your savings... have fun replacing it, and the mobo, and the cpu, and the... I also don't understand why you bothered asking for help.
a c 243 ) Power supply
February 5, 2009 10:42:38 AM

Almost $700 on mb, cpu and ram and then a $90 POS power supply ?
There are power supplies that you can get for $90 that are of much better quality than what you have chosen, you just have to being willing to shop for a deal
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

PS; never rely on Newegg reviews
February 5, 2009 6:32:39 PM

Can any1 help me. Is 11.71 on a 12v rail ok and normal on a new corsair hx1000w psu. My old psu was a silverstone 650w and the 12v rail was at 11.77 and i got a bfg gtx 280 oc2 and it keeps crashing. Bfg sed it was a power issue and the 11.77 was at fault thats why i got a new 1 but the new 1 is lower and the gtx280 still crashes as i think its a faulty gpu so is 11.71 ok as this a top notch psu. thanx kabolo1.
a b ) Power supply
February 5, 2009 7:45:09 PM

kabolo1 said:
Can any1 help me. Is 11.71 on a 12v rail ok and normal on a new corsair hx1000w psu. My old psu was a silverstone 650w and the 12v rail was at 11.77 and i got a bfg gtx 280 oc2 and it keeps crashing. Bfg sed it was a power issue and the 11.77 was at fault thats why i got a new 1 but the new 1 is lower and the gtx280 still crashes as i think its a faulty gpu so is 11.71 ok as this a top notch psu. thanx kabolo1.


BFG shouldn't have told you that, 650W is plenty and Silverstone is a good brand. You need to check the voltages with a DMM. See here.

BTW, next time start your own thread.
a c 243 ) Power supply
February 5, 2009 8:38:02 PM

theAnimal said:
BFG shouldn't have told you that

EVGA likes to use the same line ( they claim that under 11.95v is not enough ), seems that video card manufacturers want to rewrite the ATX spec.
a b ) Power supply
February 5, 2009 9:24:28 PM

To Codywolf16:
Any PSU with 138 reviews and over 25% are NEGATIVE - You STAY away from.
You take a real chance at blowing your other components. If you were a friend of mine I would be blunt and ask, Do you have more money than brains. YOU also got some very good advice and ignored it.

To kabolo1:
The 12 Volt rail you listed as 11.71 - Was that loaded or at idle. You need to check it under load. You can run Fur mark, or View 3D under ATI tools. Also as theAnimal suggested, use a DVM to verify. If under load it is above (May recomendation) 11.6 V (theAnimal's link use 11.4V) it should be fine. I would ask EVGA and/or BFG Where, in print, does it state that it requires greater than 11.6 V!!
a b ) Power supply
February 5, 2009 10:20:43 PM

RetiredChief said:

To kabolo1:
The 12 Volt rail you listed as 11.71 - Was that loaded or at idle. You need to check it under load. You can run Fur mark, or View 3D under ATI tools. Also as theAnimal suggested, use a DVM to verify. If under load it is above (May recomendation) 11.6 V (theAnimal's link use 11.4V) it should be fine. I would ask EVGA and/or BFG Where, in print, does it state that it requires greater than 11.6 V!!


The ATX spec is plus or minus 5% for +12V, of course less is always better. Apparently some cards are very picky about voltage (I don't know which).
a c 144 ) Power supply
February 6, 2009 6:18:18 AM

RetiredChief said:
To Codywolf16:
Any PSU with 138 reviews and over 25% are NEGATIVE - You STAY away from.

Oh, yes, indeed. newegg is my vendor of choice. But you need to learn how to read the reviews. Keep in mind that the negative reviews skew the percentages. Someone who receives good parts may, or may not, write a review. Someone who gets a bad part also certainly will take the trouble to write a bad review. Still, 25% bad reviews on something as critical as a power supply is pretty bad odds.

I alway read the bad reviews first. Sometimes a feature an item has or doesn't have is not important to me. OTOH, the reason I didn't buy a couple of 1.5 TB Seagate drives when I was home last Christmas was the really high rate of DOA drives. It will be a while before I trust Seagate again.

Back to PSU's and graphics cards. A graphics card pulls about twice as much power under a 3d load as a 2d load. So the 12 volt output needs to be checked under both a light desktop load and a heavy 3d load.
!