Combined Amperage....?

bumblebee_tuna

New Member
When a PSU has dual rails, is the amperage then marked as combined then? For example, my PSU has dual 12V rails at 22/20 amps.... so would the PSU then be considered to have 42 amps? or would it still be 22 amps?

The reason I'm asking this because I've been looking at video card requirements lately and some (8800GT) have been demanding 48 amps on the 12v rail and I haven't really been able to find a PSU that fits those requirements; unless the amperage was combined.......
 
the corsair one with triple 18a rails have a combined amperage of like 40 watts, so each rail is really only worth likr 70% of its actual amperage when combined
 
the corsair one with triple 18a rails have a combined amperage of like 40 watts, so each rail is really only worth likr 70% of its actual amperage when combined
Yes thats true, for example, my PSU is a quad rail at 18A each, however combined it's only around 52A.
 
When a PSU has dual rails, is the amperage then marked as combined then? For example, my PSU has dual 12V rails at 22/20 amps.... so would the PSU then be considered to have 42 amps? or would it still be 22 amps?
You can't just add them, particularly when it comes to triple/quad rail PSUs. You will usually find that the total wattage available on the +12V rails is indicated. You can divide this number by 12 to find the total amperage on the +12V rails.

The reason I'm asking this because I've been looking at video card requirements lately and some (8800GT) have been demanding 48 amps on the 12v rail and I haven't really been able to find a PSU that fits those requirements; unless the amperage was combined.......
A single 8800GTX requires only 30A. If you want to SLI G80s, take a look at the Silverstone ST75ZF, PC Power and Cooling Silencer 750W or Seasonic M12 700W.
 
You can't just add them, particularly when it comes to triple/quad rail PSUs. You will usually find that the total wattage available on the +12V rails is indicated. You can divide this number by 12 to find the total amperage on the +12V rails.


A single 8800GTX requires only 30A. If you want to SLI G80s, take a look at the Silverstone ST75ZF, PC Power and Cooling Silencer 750W or Seasonic M12 700W.

ROFL, me.... SLI G80s...... What? You think I'm rich or something....?:D

Nah, I was just wondering because I've been seeing a lot of cards requiring a high amperage...... Taking a glance at my PSU, it doesn't tell you the total amperage of both rails, so how would I go about finding out..... other than with a multimeter?
 
You really can't tell with a multimeter (not easily, at any rate).

Can you tell me which PSU it is? You'll sometimes find additional information on the manufacturer's website, but often it's nowhere to be found. There are ways to get a rough approximation, but it does depend on what info you're given.
 
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