yuhhojr :
Someone Somewhere :
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.