Where do I look at the Amp?
- Thread starter Euklid
- Start date
These minimun requirements are for the average system as a whole if your running that video card. The card doesnt pull 475W and 26amps. Your Power Supply total on the 12V rail has around 56 amps. The listing on the rail of 18 amps is just the limit any one rail can pull.
You sure?
Looks to me like that PSU pulls 18A x 4 ( 4 - 12 volt rails ) = 72Amps
I'm still learning here - but that's my understanding from what I've learned so far. Add up the 12 volt rails for the amp total of a PSU.
Nope, you just dont add the rails up. Thats the max. any (one) rail can pull before it trips the power supply.
WeatherMan
Active Member
My tagan for Instance.
4 x 20A, My actual Aperage is 48A
4 x 20A, My actual Aperage is 48A
Bodaggit23
Active Member
I'd like to see a link to the documentation about the Amperage ratings,
and why 2+2 doesn't equal 4...
To lazy to look it up. But (most) Power Supplies are not true multi rail. They are connected to a single 12V line and each line has a limit it can pull off the main 12V rail ( hence the amp limit on each rail) Kinda like a circuit breaker. But it doesnt mean that all the rails can pull there max. at the same time. The main 12V line just doesnt have that many amps. Be best way to get a average amount of amps total. Is to take the total amount of watts. on the 12V rail and divide it by 12.
How did you come up with 56 amps on the 12 Rail for the PSU then?
TFT
VIP Member
The PSU states 675 watts total available to the 12v rails.
I=watts/volts and that equals 56 amps can be drawn in total. (not allowing for inneficiency)
Each of the four rails is current limited to 18 amps but you cannot draw more than the PSU can provide off the single rail feeding them which is 56 amps.
If you added the 4 x 18 amp rails together it would amount to 864 watts and that is way above the PSU's capacity.
I=watts/volts and that equals 56 amps can be drawn in total. (not allowing for inneficiency)
Each of the four rails is current limited to 18 amps but you cannot draw more than the PSU can provide off the single rail feeding them which is 56 amps.
If you added the 4 x 18 amp rails together it would amount to 864 watts and that is way above the PSU's capacity.
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Bodaggit23
Active Member
So you're saying that all pc power supplies are 1 phase?
Example, this dual rail power supply can supply the the total amount of max. amps on both rails.
Has two rails, one 25 amp. max. and one 35 amp. max. with 60 amps total on the 12V rail.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817256049
Has two rails, one 25 amp. max. and one 35 amp. max. with 60 amps total on the 12V rail.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817256049
Your fine with the OCZ and the requirements for your card. Its just you need atleast 26 amps for the whole system.
From what I have saw the 9800GTX+/GTS 250 just pulls around 10 amps max. just by itself. As far as watts. A PCIe slot depending on the version can supply 75/100W, the PCIe 6 pin power connector can supply 75W. So the most watts the card can pull is 150/175W. Or if it has 2 PCIe 6 pin power connectors it can pull up to 225/250W.
From what I have saw the 9800GTX+/GTS 250 just pulls around 10 amps max. just by itself. As far as watts. A PCIe slot depending on the version can supply 75/100W, the PCIe 6 pin power connector can supply 75W. So the most watts the card can pull is 150/175W. Or if it has 2 PCIe 6 pin power connectors it can pull up to 225/250W.
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