Is my power supply powerful enough?

How much power is enough for your PC?

There's nothing to calculating how many watts your PC will need to operate properly. You total up the power needs of your processor, your motherboard, your video and sound cards, and everything else that goes inside your computer, round up to the capacity of a decently-priced power supply, and there you have it. Of course, you have to know the power needs of your processor, your motherboard, your video and sound cards, and everything else that goes inside your computer, but what's life without its challenges.

Actually, you don't. The manufacturer's web site will almost certainly include those specs. So will the sites for many stores selling the units.

But there's an easier way: Use a power supply calculator. These web sites, usually free, let you select components, then calculate the total. One problem with all of them: They don't list every component under the sun. If they don't list, say, your video card, pick another in about the same price range and you'll probably be close enough. Remember, this is all approximate, anyway, so it's best to err on the side of too much power.

Here's what I think of three such calculators, in order of preference.

Newegg: This one is simple and direct, and if it errs, it errs on the side of caution, recommending a too-big supply over an inadequate one.

eXtreme: More detailed than the others, it offers more components and asks more questions. Not surprisingly, it can intimidate the novice user. And according to some folks on the Answer Line Forum, it tends to guess low, which can run into problems.

It's worth noting, however, that the US$2 Pro version of eXtreme's calculator can calculate not only how many watts you need total, but how many of those you need in 12, 5, and 3.3 volt form.

Journey Systems: Once well regarded, Journey Systems calculator is now quite out of date. They know it, and are promising a new one.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags power suppliesdesktop pcs

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lincoln Spector

PC World (US online)
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Cate Bacon

Aruba Instant On AP11D

The strength of the Aruba Instant On AP11D is that the design and feature set support the modern, flexible, and mobile way of working.

Dr Prabigya Shiwakoti

Aruba Instant On AP11D

Aruba backs the AP11D up with a two-year warranty and 24/7 phone support.

Tom Pope

Dynabook Portégé X30L-G

Ultimately this laptop has achieved everything I would hope for in a laptop for work, while fitting that into a form factor and weight that is remarkable.

Tom Sellers

MSI P65

This smart laptop was enjoyable to use and great to work on – creating content was super simple.

Lolita Wang

MSI GT76

It really doesn’t get more “gaming laptop” than this.

Featured Content

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?