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Do dual rails add?

post #1 of 3
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Simple question: if you have a dual rail power supply, do you add the amps of each 12V rail to get total 12V amperage? For example... my power supply has a 14A and a 16A rail. Does that mean I have 30A total? And doesn't that seem like a bit much for a 420watt power supply that came free with my case? I'm trying to figure out if it will run a new 7900GT or GTX.
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post #2 of 3
Yes they add, It may or may not run it. But most likely should. I've heard of my PSU running 7800's with a san diego thrown in the mix, and it's only 400 watts
    
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post #3 of 3
yes you add the amperage on all the +12v rails to get the total... but FYI, wattage doesnt really mean much... IE: my 400watt antec has 24A on the +12v rail, but my cheapy 500watt PSU has 16A on the +12v rail... rail amperage is what matters most

i think the 30A is enough to run a new 7900...but not 2!
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