Web App of the Week: eXtreme Power Supply Calculator
One of the most common questions of PC building is, "How much power do I need?" And while I realize that most Maximum PC enthusiasts might very well just answer the question thusly--"As much as I can buy"--that's not always the best recommendation for two key reasons: You don't need a kilowatt power supply if you're rocking a newb rig, and you might not have the budget to afford more juice than what your computer ultimately requires.
But how, then, do you figure out the exact size of power supply your system requires for perfect performance? It's no easy task. I highly doubt you want to arm yourself with a clipboard and surf over to the manufacturers' Web sites to figure out the power draw for all the components in your rig. And even then, you're not going to have an easy time doing so. You'll probably just go off the recommendation of someone from an online message board--"oh, so and so rig usually needs... 700 watts at least. You'll be fine then. Word."
Okay.

That, or you could hit up this week's Web App pick: the eXtreme Power Supply Calculator. This super-helpful online tool gives you a comprehensive list of components to pick from. Select what's in your PC and you'll get an read-out of how much power your system will likely draw in the form of a recommendation for the specific-sized power supply you should pick up. It's as easy as that.
But just how comprehensive is this tool? You can pick:
- Motherboard type
- CPU type (by actual product)
- RAM
- Video card (by actual product)
- Hard drive (by RPM)
- SSD
- Optical drive(s) (by type)
- PCI cards (by type)
- Miscellaneous PCI Express cards
- External USB or FireWire devices
- Cold Cathode lighting
- Fans (by size and type)
- Coolers (by type, with extra information for water coolers)
In short, if you aren't using the eXtreme Power Supply Calculator, there's a good chance you could be running a power supply that's too big or too small for your system's needs.
Every Thursday, Maximum PC picks a new Web App as its favorite of the week. Have a Web App that you can't live without? Twitter David Murphy @acererak with your latest suggestions.
Comments
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Chebornek
December 21, 2010 at 11:47am
75% of the manufacturers hide their power consumption ratings for their various parts and you really have to dig to find those webpages (then you have to bookmark them). Forget about finding any BTU output for the heat those parts generate. Why this is a some kind of huge secret, is beyond me, unless 'they' are ashamed of the numbers. This is a handy tool for those who know how to go find that information, (and those who don't) but would rather not spend half a day tracking all that information down for every peripheral in their cases.
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jimc52
July 24, 2010 at 11:05pm
I can estimate the power consumption of just about any hardware on my own...which means, I don't need to PAY THEM to tell me I am right. All you have to do is do a little specification studying for most harware which is available on the net for just about everything - IF YOU LOOK. So what if it takes me 15 minutes to come up with it? I didn't have to pay a penny is my point. If they had offered this for free, I could see it being a nice little utility, but frankly, I am sick and tired of being nickled and dimed by everyone for everything, and just saving me a few minutes doesn't ring up on my cash register. Tell them to make it free and I will consider it.
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blueguile
August 26, 2010 at 10:03am
Well if you like to take the time to search the net for the power requirements for all your hardware, feel free to do so. Using this web app that is for FREE and taking 2 minutes to do so is awesome. I doubt that it takes 15 minutes to find the power requirements for ALL your hardware. Maybe 30 minutes to an hour is more like it.
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JohnP
December 21, 2009 at 2:27pm
I did my own calculations when doing the build and came up with 495 watts and this app came up with 487. Within 3% is close enough! I have a 750W power supply so I do not have to worry much. Thanks for pointing this out MPC!
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