Deciding between 550W & 650W - help!!

Bearget

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Jun 13, 2012
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I'm trying to choose between these two power supplies:
XFX Core Edition Pro 550W
XFX Core Edition Pro 650W

Both are highly rated. The second one is $10 cheaper, for 100W more.

My only concern is, could it be overkill? I know extra wattage isn't going to damage anything, but I'm not sure it's going to be running efficiently. This calculator recommends 465-495W for my build, while this one specifies a minimum wattage of 310-330, and recommends something in the range of 350-380.

I don't plan on overclocking or running multiple video cards any time soon. Is the 650W going to be running too light a load to work efficiently? If so, will the inefficiency ever add up to the $10 difference? And if I decide to overclock down the line, will the 550W give me enough room to do that?
 

jacknhut

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I would get the 550W if you dont plan on SLI. If you do plan on SLI, 10 bucks more to get 650W is worth it.
 

Bearget

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Jun 13, 2012
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Thanks for the replies! My concern isn't so much about whether 550W will be enough. I'm more worried that the parts I'm looking at will only draw ~310W, in which case it would be sub-50% load on the 650W psu. Though I suppose it's really not that far outside the optimal range...
 

Shinseina

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Apr 1, 2012
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Bearget,

What this comes down to is the efficiency of the power supply, not the size.

It's apparent that either power supply would work for you, and for an XFX power supply (highly rated) the price is amazing.

Getting a 700W for $40.00 would be silly as the brand is probably Apevia or something and their quality of power supplies is much less than XFX.

As for the efficiency, you don't need to worry about that. If you use a 650W power supply and your computer pulls 380W, you will pull ~380W.

This also holds true for the 550W, if your computer pulls 380W, with this power supply you will only pull ~380W from the power supply.

Since they are the same brand, both are 80 plus certified, the 650W is $10 cheaper, AND the 650W can take a load up to ~100W more than the 550W power supply, you should go with the 650W power supply :)


Happy building,

Shinseina
 

angaddev

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