How much extra wattage when picking a power supply?

[subsidedmold]

I have all my parts shipped except for my power supply, on pcpartpicker, the estimated wattage is 270w. My build has an i3 8100 and a 1060 3gb, and I am deciding weither to pick a 450w or a 550w because both seem to be on sale, the problem is that I heard somewhere that if I pick a power supply with to much extra wattages then my parts will not be working less and not fully.

 

[TJ Hooker]

You heard wrong, there's really no downside to using an overpowered PSU. Well, it may run slightly less efficiently depending on the ratio of actual load to rated capacity (PSUs are typically most efficient around 50% load), but it's not a big deal. If the 450 and 550 W units are about the same price, I'd get the 550 W. What particular models are you looking at?

 

[subsidedmold]

You heard wrong, there's really no downside to using an overpowered PSU. Well, it may run slightly less efficiently depending on the ratio of actual load to rated capacity (PSUs are typically most efficient around 50% load), but it's not a big deal.

So ill be fine with the 550w if my pc uses about 270w

 

[TJ Hooker]

Yes, absolutely. Which 550W unit are you looking at?

 

[subsidedmold]

Yes, absolutely. Which 550W unit are you looking at?

https://www.amazon.com/dp/B01B72W0A2/?tag=pcpapi-20

 

[SkyBill40]

When buying a PSU, you have to consider your current setup and any potential growth or upgrades you might perform on that same unit. You're not going to do anything negatively by buying a PSU that's over what your setup may require at max power draw. Look at it this way: It's better to have the power and not need it than to need it and not have it.

The 550w unit should be fine. Buy a quality part and you'll be good for many years to come.