Overkill PSU is BAD ?

[Tost TheGrenade]

i'm new to " PC MASTER RACE " . i wanna ask dat if a a overkill PSU will be bad for ur build ? . like if i take i7 4790K GTX 970 and use a corsair RM 750 PSU , can it harm my PC ?

 

[Enderman]

Nope. its actually good because under load it will be working at its peak efficiency (about 50%) and it will also be quieter at idle than a lower wattage PSU.

[TheKDub]

Nope, an overkill psu will not harm your pc at all.

 

Now a shitty quality psu, that can harm your pc.

[ELSknutson]

no if you have a good PSU It will only use the power it needs and throttle back to save power. but if it doesn't have toughs features it will just use wast more electricity 

[quan289]

It might be marginally inefficient.

You spend more money on something that you don't need.

[Antistatic12]

If you value silence, then a high end PSU (like a AX1200i) will be your best friend.
As it basically wont make noise until you start gaming/editing/other load heavy tasks.

Also if you are not sure what PSU to get. Basically anything Jonnyguru says is good, is worth buying.

[Peter Vaughan Truslow]

with an overkill PSU you will be overspending, have more cables than you will know what to do with if it isn't modular, and have high idle power consumption because bigger power supplies draw more power when on, even without almost no load at all.

won't damage anything though. I got a 1000 watt PSU for 100 dollars and I don't have too many regrets apart from the 90 watt idle power when it could be around 40-50 watts or so

[AlexStriz]

It might be more inefficient, but it's typically marginal.

I've always wondered, why do people say that? What is there about a higher watt PSU that makes it more efficient? Genuinely interested. 

[Rorro]

nop you will be better off!

[crystal6tak]

What they are saying is the efficiency.

 

Errm. Like. For example if you have, say a 1200w PSU on a system that on load uses 500W.

 

At 500w, which is 42% load on the PSU. The PSU may be 80% efficient.

However, at 900w, which is 75% load. The PSU may be 95% effecient.

 

So if you use a PSU that's extreme overkill on your system you MAY be losing out on efficiency. It's different for all PSU though. To check the efficiency on % load check jonnyguru.

 

It's not bad for your system. Doesn't hurt anything except maybe your electric bills.

[NumLock21]

Overkill PSU, more things you can throw at instead of worrying about will my PSU be able to handle this or that.

[quan289]

I've always wondered, why do people say that? What is there about a higher watt PSU that makes it more efficient? Genuinely interested. 

 

Depending on how much the components draws, a higher wattage unit may be more or less efficient. Efficiency would start out low and increase up to a certain load. Once it gets to that particular load, efficiency start to decrease again. The peak efficiency is typically around the 50% mark (may be at a higher or lower load depending on the unit). Since the OP system will draw around 275wDC during gaming load, a 550w system may be more suited for his system than the 750w which is only putting about a 33% load.

 

You could also say that since it is running less efficient, it is actually getting a little hotter, as it is putting out more heat.  Of course, efficiency difference between in load isn't that big after 20% load. As you can see in this review of the RM750, there's about only a ~2% difference between 20% and it's peak. http://www.techpowerup.com/reviews/Corsair/RM750/6.html