How much power does this power supply actually make?

I'm looking at the power supply from my computer and the two lines of text that mean anything to me read:

+5V & +3.3V 120W MAX.

The Total Power Max 250W

This is kind of confusing to me, which number is actually my max wattage? 120W or 250W? I'd like to know so I can judge whether or not it can handle my new video card.

Thanks in advance.

4 Answers

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  • 9 years ago
    Favorite Answer

    This has to do with the rails. That power supply produces 120W MAX on the +5V and +3.3V rails. That means that the 12V rails will put out the rest.

  • Dan B
    Lv 7
    9 years ago

    Your power supply will handle the graphics card especially if you remove the graphics card you plan on replacing. It's not really a power hungry item (unlike the HDDs and CPU).

    The 3.3v is derived from the 5v supply. So a total of 120w can be drawn from these sources in any combination. The 3.3v is used for the CPU and uses a few watts of power. The remaining power from the 5v line is used to power the rest of the motherboard and plug-in cards.

    The rest of the power on the 12v lines (used for the disk drives) is 130w max (just a little over 1 amp). If you connect several internal HDDs, you may run into a problem with power.

  • ?
    Lv 7
    9 years ago

    That is a 250w Max power supply. I'll be honest that won't be nearly enough for even a half decent graphics card.

    I'd upgrade the power supply, get a 500w 80plus power supply (OCZ, Corsair, Antec) and this will be all of the power you ever need for a system with a single graphics card.

    Don't worry about the wattage it would be drawing from your wall socket. It will only draw the amount of power it needs, which will hardly ever be the full 500w, which is the maximum the power supply can provide

  • 9 years ago

    Your supply is rated to deliver 120W full time ( 1 amp ). 250W is the total it will draw from the wall ( this includes power for the heat that the supply generates )

    Source(s): Electric industry 30yrs and computer geek
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