Advantages and Disadvantages of Having A Bigger PSU Than Needed?

[IAEInferno]

So I was wondering if there are any disadvantages like more power usage on using a bigger PSU that what you really need like for example.

 

I will use a 850W PSU on my rig that only consumes around 530W at maximum, does that mean that I will have bigger electricity costs or will it only use the 1-530W of power instead of the full 850W?

 

I'm planning on using the 850 because I might do an SLI/Crossfire in the future.

[thekeemo]

you will only use 530

[79wjd]

Advantages: more headroom for the future

Disadvantages: More expensive and likely lower efficiency (peak efficiency is usually around 50%, and you're system is probably drawing far less than 530w under load and it likely won't be under full load the majority of the time). 

[shadowbyte]

absolutely none

your PC just uses what it needs

[Energycore]

2 minutes ago, IAEInferno said:

So I was wondering if there are any disadvantages like more power usage on using a bigger PSU that what you really need like for example.

 

I will use a 850W PSU on my rig that only consumes around 530W at maximum, does that mean that I will have bigger electricity costs or will it only use the 1-530W of power instead of the full 850W?

 

I'm planning on using the 850 because I might do an SLI/Crossfire in the future.

Advantages:

 - It might run fanless for longer times when you hit it with a load.

 - It might last somewhat more time (this claim is unconfirmed)

 - Better efficiency at half load may save you a percent or two on the electric bill (do the math yourself if you care)

Disadvantages:

 - More expensive

 - Larger

 - More cables or modular connectors that are unused

[The1whokill5]

1 minute ago, shadowbyte said:

absolutely none

your PC just uses what it needs

Agreed, a bigger supply just gives you more cushion for the future, and your usage will fluxuate more power when under heavy load less when you don't need it. But the psu is a transformer essentially and shouldn't take to much to power

[IAEInferno]

Just now, Energycore said:

Advantages:

 - It might run fanless for longer times when you hit it with a load.

 - It might last somewhat more time (this claim is unconfirmed)

 - Better efficiency at half load may save you a percent or two on the electric bill (do the math yourself if you care)

Disadvantages:

 - More expensive

 - Larger

 - More cables or modular connectors that are unused

 

 

The 850W one is only $4 more expensive than the 750W, would getting the 850 be worth it?

[79wjd]

Just now, IAEInferno said:

The 850 one is only $4 more expensive than the 750W, would getting the 850 be worth it?

What are the two PSUs? 

[IAEInferno]

Just now, djdwosk97 said:

What are the two PSUs? 

EVGA SuperNova 750W and 850W P2 80+platinum.

[Energycore]

Just now, IAEInferno said:

The 850 one is only $4 more expensive than the 750W, would getting the 850 be worth it?

Yeah, I would say so.

[Godlygamer23]

Efficiency and cost. 

[The1whokill5]

1 minute ago, IAEInferno said:

The 850W one is only $4 more expensive than the 750W, would getting the 850 be worth it?

 

1 minute ago, djdwosk97 said:

What are the two PSUs? 

 And what are they rated at? Bronze gold plat?

[79wjd]

Just now, IAEInferno said:

EVGA SuperNova 750W and 850W P2 80+platinum.

Then yes.....but I'd look at something cheaper altogether (G2 750w for example). 

[The1whokill5]

Go with the 850 plat

[IAEInferno]

Just now, djdwosk97 said:

Then yes.....but I'd look at something cheaper altogether (G2 750w for example). 

So there really isn't too much of a difference between G2 and P2?

[IAEInferno]

Just now, djdwosk97 said:

Then yes.....but I'd look at something cheaper altogether (G2 750w for example). 

If I added an SLI then the power I need would go up to 745W at maximum load for my rig, isn't 850W safer?

[79wjd]

1 minute ago, IAEInferno said:

So there really isn't too much of a difference between G2 and P2?

Not enough to warrant spending more than like $10. 

 

The P2 is an overall better unit and has a higher efficiency. But the G2 is almost just as good and usually FAR cheaper. 

 

Just now, IAEInferno said:

If I added an SLI then the power I need would go up to 745W at maximum load for my rig, isn't 850W safer?

What GPU/CPU do you have? 

[IAEInferno]

Just now, djdwosk97 said:

Not enough to warrant spending more than like $10. 

 

The P2 is an overall better unit and has a higher efficiency. But the G2 is almost just as good and usually FAR cheaper. 

 

What GPU/CPU do you have? 

 

my planned build will have the gtx 1080ti which has 250W and im gonna probably use the new kaby lake i7-7700k when it gets released.

[79wjd]

1 minute ago, IAEInferno said:

my planned build will have the gtx 1080ti which has 250W and im gonna probably use the new kaby lake i7-7700k when it gets released.

A 750w would be more than enough. But again, if an 850w unit is similarly priced, then spend a few extra dollars. (anything from tier 1 or 2 from the PSU tier list in my sig is good). 

[IAEInferno]

Just now, djdwosk97 said:

A 750w would be more than enough. But again, if an 850w unit is similarly priced, then spend a few extra dollars. (anything from tier 1 or 2 from the PSU tier list in my sig is good). 

 

Are the ones from tier 1-2 better than the ones along tier 3-7?

[79wjd]

3 minutes ago, IAEInferno said:

Are the ones from tier 1-2 better than the ones along tier 3-7?

Significantly. 

 

Tier 1 - I have money to blow

Tier 2 - I'm building a top tier system 

Tier 3 - I'm building a semi-budget system (not top tier, but I have just barely enough to get a 1070) 

Tier 4 - I'm building a budget system and I can barely afford this 470/380/960.