Does Higher Wattage PSU cost more electricity bill?

[yuhhojr]

Hi,

I'm planning to get EVGA Supernova 550W G2 PSU, but unfortunately they don't sell it on my country, they only sell Supernova 750W G2. My question is, will it effect my electricity bill if I'm using higher PSU? Im using i5 6600k and for GPU is EVGA GTX 1060 6gb FTW+Gaming.

Thanks

 

[Someone Somewhere]

Nope, effectively no difference.

 

[yuhhojr]

Nope, effectively no difference.

So the PSU only draws power depend on my PC needs (for ex, let's say my pc max watt will be 500 watt)?

Thanks

 

[Someone Somewhere]

Plus the efficiency of the power supply - but those are both Gold, so should be similar.

 

[yuhhojr]

Plus the efficiency of the power supply - but those are both Gold, so should be similar.

Thanks for the reply. If I may know, how do you calculate the wattage will the PSU take from wall (let's say max will be 500w for my PC)? and how many wattage difference if using 550w G2 and 750w G2?

 

[maxalge]

Plus the efficiency of the power supply - but those are both Gold, so should be similar.

Thanks for the reply. If I may know, how do you calculate the wattage will the PSU take from wall (let's say max will be 500w for my PC)? and how many wattage difference if using 550w G2 and 750w G2?

easiest way is to use a kill a watt monitor

none, if your system draws 500w both will deliver 500w , the 550 g2 would just work harder to deliver that power, thus it may run hotter with the fans at a faster speed to keep itself cool

 

[Isokolon]

Your parts are rated for a Power target.

For example a GTX1080 is rated for 180W, some aftermarket versions for 220W.
An i7-6700k is rated for 91W
16GB DDR4 RAM consume between 15-25W
Motherboards can use up to 80W, most stay well below 50W in terms of power consumption.
The easiest way is to calculate CPU+GPU+100W, taking the parts above this runs to around 380W, now you add 15-20% headroom for your PSU - a 450W quality PSU could handle this probably.

If it's a quality unit with gold efficiency the difference between running it at full load and half.load is usually not more than 2-3% in efficiency
If you'd be drawing 500W from the PSU the 550W unit would draw for example 550W (=90% efficiency) while the 750W unit would draw 540W (=92% efficiency) from the grid (not exact figures)
But honestly that's within the margin of error as well.

 

[UnspokenWhale]

Plus the efficiency of the power supply - but those are both Gold, so should be similar.

Thanks for the reply. If I may know, how do you calculate the wattage will the PSU take from wall (let's say max will be 500w for my PC)? and how many wattage difference if using 550w G2 and 750w G2?

This page shows the 750w gets 88.7% efficiency at 600.1W/676.5W and 90.1% efficiency at 377.8w/419.4w (I'm not gonna do the math on that one, so I just averaged it at about 89.4% efficiency at 500w), while this page shows the 550w gets about ~87.5% efficiency at ~500w (give or take 0.5%).

In theory, the 750w should draw about ~559w and the 550w should draw about ~571w, both with a load of 500w. Meaning the difference is about 12w. The 750w costs $108.89 and the 550w costs $85.45, a difference of $23.44. Assuming you pay $0.11 per kw/h that's about 17,758 hours of operation to get your money back, or about 6 years assuming you run your computer at 500w 8 hours a day.

I probably got something wrong in my calculations but it's generally accepted that you aren't really going to be making any money back by buying slightly more efficient parts at greatly increased costs.

 

[Isokolon]

How do you get to 17.758h ??
That's around 1900$ at 0.11$\kWh

You'll need 213h to equal the pay difference
But the point is valid, 213h @full load is a looong time.
Furthermore I highly doubt your system will draw that much power anyway

 

[UnspokenWhale]

How do you get to 17.758h ??
That's around 1900$ at 0.11$\kWh

17,758 hours @ 12w is 213.096 kWh. So $0.11 per kWh is $24.44. Is this not correct?

 

[yuhhojr]

wow, thanks for reply guys, really appreciate your help

 

[Isokolon]

Sorry you're absolutely right.
Overlooked the kW vs. W conversion.