Can you have a too high wattage psu ?

RJC

RJC

Don
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A PSU will only draw whats needed, but as most high end PSU have a energy rating and these need to be within a certain limit to come into affect I think around 60% load ~

Your system can pull less than what you think.

My system in my sig pulls 330w from the mains at full load, can you post your system specs.
 
Soldato
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It'll increase electricity bills and the cost of the PSU if you overspecify it. It wont hurt the computer.

Power supplies are most efficient at something like 80% load (varies a bit between supplies). So a 1kW power supply will use less electricity than an 800W supply, when both are driving a 750W load. Similarly they're really inefficient at low wattage - using a 1kW supply where a 100W one would suffice will waste electricity.

Finally, if you buy a 1kW supply which costs the same amount as a 500W supply, it'll be crap. You don't want a crap PSU because it's apt to blow up and destroy your motherboard.

If you post what it'll be powering, you'll get a recommended wattage / list of power supplies :)
 
Associate
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If your PSU is capable of providing more than you need, your system will consume only as much as it requires.
If, for instance, your PSU is 1000W and your system really needs only 500W, your electricity bill will be for 500W, not 1000W.
 
Soldato
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Well... yes and no...

Technically you cant have too powerful a PSU, but if you system is using 400W and youve splashed out on a 1200W PSU then your efficiency decreases.

The rule of thumb is to calculate your max system wattage as 60% of the PSU's maximum.
 
Associate
OP
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Should I change it to one of these ? And do I need 850w psu ?

CoolerMaster 850watt Silent Pro M2 Modular Gaming Power Supply, SLI / Crossfire ready

Corsair 850 Watts TX850M Enthusiast Series Modular Gaming Power Supply
 
Man of Honour
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As someone mentioned above buying a higher wattage PSU over a better brand lower wattage PSU can be a bad idea.

Most PSUs work most efficently within a certain band of their power handling capabilities so often a higher than required rating PSU can result in cleaner and more efficent power supply than one thats closer to its limits however this can also potentially mean that you fall through the bottom of its most efficent band if you overspec too far but generally the risk of that is very minor.
 
Associate
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A PSU will only draw whats needed, but as most high end PSU have a energy rating and these need to be within a certain limit to come into affect I think around 60% load ~

Your system can pull less than what you think.

My system in my sig pulls 330w from the mains at full load, can you post your system specs.

Wow, surprised with that. That means your system actually uses about 264w :)
 
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