A stupid question on PSU's

[LegacyStijncat]

Hello, and thanks for reading this already!

 

I'm no expert on PSU's, nor am I on power consumption. So here comes a very stupid question, but hey, asking never hurt anyone I guess.

If you grab an 800W PSU instead of a 400W PSU in the same identical system, would that mean the system uses more power in the 800W?

 

Thanks in advance!

 

(I know it's a stupid question, but I'd rather have the electricity bill to not be... shocking! _{I'll see myself out})

[Overkilled]

No it just means you have more headroom

[TheRandomness]

Short answer: No.

Long answer: It will use the same amount as it did before.

[SeanAngelo]

Hello, and thanks for reading this already!

 

I'm no expert on PSU's, nor am I on power consumption. So here comes a very stupid question, but hey, asking never hurt anyone I guess.

If you grab an 800W PSU instead of a 400W PSU in the same identical system, would that mean the system uses more power in the 800W?

 

Thanks in advance!

 

(I know it's a stupid question, but I'd rather have the electricity bill to not be... shocking! _{I'll see myself out})

no. it depends on the components you use. if its the same components for both power supplies, then they will eat up the same power.

 

having a 800W power supply just means you have more headroom.

[Enderman]

it means it CAN use more power if it needs it

but if it uses less than 400W then it will use the same power on both (unless the 400W one is lower efficiency or something)

[daniellearmouth]

This is gonna sound a bit complicated, so bear with me...

 

No. Your computer will use as much power on a 500W PSU as it would an 800W PSU, a 1000W PSU or even a 1500W PSU.

 

There are, however, two things to note.

Firstly, using a power supply whose rated output is significantly greater than that of the computer itself (like, over twice, if not three times as much output as you need), then you will see reduced efficiency.

Secondly, it's always a good idea to get just a bit more than what you need for a power supply. This may sound contradictory to the last point, but it allows for growing room, should you ever want to put more powerful hardware in, and ultimately, it doesn't hurt to have a bit more juice in your PSU than what you need. Though again, three times the juice you need means wasted juice. Insert more juicy analogies here.

[Coaxialgamer]

Hello, and thanks for reading this already!

 

I'm no expert on PSU's, nor am I on power consumption. So here comes a very stupid question, but hey, asking never hurt anyone I guess.

If you grab an 800W PSU instead of a 400W PSU in the same identical system, would that mean the system uses more power in the 800W?

 

Thanks in advance!

 

(I know it's a stupid question, but I'd rather have the electricity bill to not be... shocking! _{I'll see myself out})

It really depends how efficient it is .

 

For example if both power supplies are at 85% efficiency at that load  , they should use the same amount of power.

 

However , if the 800w is running at 80% at that specific load and the 400w is running at 88% , you will see a difference in power usage

[EmeraldFlame]

-snip-

 

Yes and no. You should see very similar power usage. However depending on the exact efficiency curves of each unit you may see a power difference. Most power supplies tend to hit peak efficiency around 50-60% load and have less efficiency at the extremes (1% and 100% usage). So if using 400W on an 800W rated power supply may in some cases use LESS electricity than 400W on a 400W supply. Or the 800W supply may be significantly less efficient across the board say a 400W 80+Gold vs an 800W 80+Bronze. In that case, it is likely the 800W would use slightly more, however the difference at the wall should be minimal ~10%.

 

Secondly, it's always a good idea to get just a bit more than what you need for a power supply. This may sound contradictory to the last point, but it allows for growing room, should you ever want to put more powerful hardware in, and ultimately, it doesn't hurt to have a bit more juice in your PSU than what you need.

 

As another point to add, as your computer, or more specifically the capacitors, age, they tend to use slightly more power. Typically it isn't enough that you notice but if you are using 399W on a 400W power supply after a couple years your computer may need 405-410W because of decreased efficiency and that can cause some issues.