enough amps but does it deliver enough Watts??? (PSU)

Lauw

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Like what if there is a PSU with enough Amps on the 12v rails but doesnt deliver the amount of Watts (on the 12v) rail that one needs for their system.

I know there are a bunch of other treads about this but it didnt make my confusion go away.

To be more specific:
Corsair VS450 delivers enough amps (36A) to power a 150W GPU but is the 432W (on the 12v rail) enough for the system?

Or is all that matters really the amount of Amps.
Like YOLO it and say: "MEH!!! we DONt need WATTs." And "Amps will solve all your life problems." LOL

Euhm... so yeah This got me confused a little.
Can anyone elaborate on this? Thanks

 

Gam3r01

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In theory yes.
However, PSU manufacturers can use split rails, as well as poor efficiencies to kinda fudge the numbers a bit.
If its a quality unit, you can generally just look at how many amps you need, the watts are a more "general" way to consider power needs.
 

Lauw

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Thanks for the reply but that didnt really answered my question. I just used the VS450 as an example.
 

Gam3r01

Titan
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Thats not how it works, if the system has sufficient amps on the 12v rail then it would have to have enough watts.
W=A*V, so if you are looking at the 12v rail, and have enough amps, you would have to have enough watts.
 

Lauw

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Okay so if you have enough Watts on the 12v rail you automaticly have enough Amps and vice versa ?
 

Karadjgne

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Everything needs to be taken with a grain of salt. The 12v rail is the most important as that's supplying the majority of power to a modern pc. It's used by the cpu, gpu, fans, etc. So the amperage output and consequent wattage there are important. No so much for total wattage. A 500w psu is not 500w. It's generally @440w+ on 12v and 20-30A on 3.3v and 5v+ rails, so that's really complete fiction as to the total wattage. The 500w is the manufacturer saying this is supposed to be what can be expected from all the rails outputs simultaneously and stay within rated temps. More often, the 3.3v and 5v+ rails (while still having separate Amps) will have combined wattage output max.

So recommendations for a particular size psu to accommodate a particular gpu are more on a general assumption that there's going to be a commensurate amount of amps available on any particular rail to not only run the pc safely and within specs, but also takes into consideration the differences between psu builds and platforms.

With a 500w recommended, you can generally get away with using a great quality 450w, but also I'd use a not-so-great 550w. However, junk is junk no matter what size, if you see a 700w with a single pcie 6pin, take it for granted it's a total pile of **** and should be avoided no matter what price it's at.
 

Lauw

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Thanks for the effort. And yes i figured it would be something a long those lines.
I wasnt completely sure about the Amps though because i see a lot of people talking more about the Amps of a PSU than about Watts.

Gamer 01 you got the win though. Thanks
 

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