The PSU & The Eletricity bill!

[LukeJ1234]

Hey there folks me again . I am currently getting a 750W PSU will it effect/affect my eletricity bill much like would up much ?

[Cohacq]

It wont draw 750w all the time. It will draw whatever the components need. Look up the power draw of your components (from testing sites, not the official PSU need, they're usually inflated) and use that as a measuring stick for your power bill. But those figures are usually for 100% load, and a computer will NEVER be on 100% unless you're doing tests.

[TheRetiredSlave]

It depends on how much power your system is drawing.. The wattage of the PSU only affects the maximum power the PSU can supply to the system, and it doesn't really affect the power draw from the wall.

 

Efficiency will vary from PSU to PSU, but for the most part the max output of the PSU doesn't affect your electric bill.

[LukeJ1234]

So like how of

 

It depends on how much power your system is drawing.. The wattage of the PSU only affects the maximum power the PSU can supply to the system, and it doesn't really affect the power draw from the wall.

 

Efficiency will vary from PSU to PSU, but for the most part the max output of the PSU doesn't affect your electric bill.

So i need a theory to prove to someone that it doesnt affect it but if it did how much would it Be like 5 euro or etc ?

[Glenwing]

750W isn't related to the amount of power the machine draws.  That just means the PSU is rated for up to 750W of power draw.  The actual power usage depends on the CPU and graphics card and how much load they are under.  Power supplies are less efficient near their maximum rated load, so an increase in your power supply might actually make your machine more energy efficient.  Although the difference is probably not worth mentioning, and only to a point; PSUs are also less efficient at very low power draw.  A PSU rated for around 2x the power your machine draws is usually the most efficient, on paper anyway.

[LukeJ1234]

750W isn't related to the amount of power the machine draws.  That just means the PSU is rated for up to 750W of power draw.  The actual power usage depends on the CPU and graphics card and how much load they are under.  Power supplies are less efficient near their maximum rated load, so an increase in your power supply might actually make your machine more energy efficient.  Although the difference is probably not worth mentioning, and only to a point; PSUs are also less efficient at very low power draw.  A PSU rated for around 2x the power your machine draws is usually the most efficient, on paper anyway.

Ok thank you for the help

[TheRetiredSlave]

So like how of

 

So i need a theory to prove to someone that it doesnt affect it but if it did how much would it Be like 5 euro or etc ?

 

Well what are you trying to compare and what are the system specs? 

 

Like Glenwing said, PSUs are generally most efficient at around 50-60 % load, so it would be most efficient to buy a PSU that's rated for twice the power draw of your system. If you're talking about a 4670K + 780 rig which would probably draw about 350 watts at load, a 650W or 750W PSU would be the best choice.

 

Anywho, the efficiency of the PSU wouldn't really affect the power draw from the wall by more than a couple watts, which wouldn't make a noticeable difference in your electric bill. Still, you shouldn't go out and buy a 1000W PSU for a 350W system just like you shouldn't buy a 450W PSU for a 350W system, but you probably wouldn't see much difference on your power bill at either of those extremes..

 

 

As a general rule, buying a good quality 650W or 750W PSU is the best choice.

 

Edit: just for funsies, I'll toss a graph of PSU(Seasonic S12G 650W) efficiency from a recent Anandtech article.