Hello today i went to Maplin to see the prices of PSUs for my i3 build and i have a question the xfx 450 costs 35 pounds and the xfx 680 is 30pound because of the half price so should i get the 680 so if later upgrade it will be fine and if i get the 680 will it take much more electicity when off or sleep? My build is
Asus usb 3 mobo forgot the name (im on the bus)
2x4gb corsair xms3 1600mhz cl9
Getting the 680w PSU will be much better for future upgrades.
You will NOT pull more electricty from your wall with a bigger PSU. You will pull more energy from the wall depending of what parts uses energy.
A PSU of 820w does not uses those watts, it means thats the max wattage it can convert from the wall to energy usable for your parts. So if you have efficient parts, you will use little power. If you have high performance parts, those will need a bigger PSU that is able to handle a load...
I hope that my rough explanation can help, any futher info how a PSU works there´s a lot of threats with very good information.