Power Suppy Question Tags: Power Supplies Energy Power Components Last response: November 12, 2012 8:24 PM in Components Share Stylo November 12, 2012 6:25:42 PM Hey all. Does a 700W PSU and a 500W PSU same brand in the exact same system draw the same amount of power/energy use? Basically I want to upgraded my PSU first to a 700W and want to know if I put it in my current system will it become less energy efficient. More about : power suppy question | E-mail me updates | Report abuse Register or log in to remove Z1NONLY Power supply Authority November 12, 2012 7:03:03 PM PSU's pull only what is demanded from them plus whatever they need to supply that power. The more efficient the PSU the less power it needs to do it's job. So a newer, mor efficient 700w PSU could end up pulling less power from the wall outlet than an older, less efficient PSU. | Report abuse TheBigTroll Power supply Authority November 12, 2012 8:24:05 PM if you upgraded to a low end 700w vs a high end 500w, you would be losing more than what you will be gaining anyways, efficiency of the unit is determined by how much power you are drawing. power supplies tend to be most efficient when the load is around 40-60% of the rated output of the unit therefore for a 500w, assuming it can output 500w on the 12v rail, will be most efficient when the system is drawing 250w for a 700w, assuming it can supply 700w on the 12v rail, it would be most efficient at around 350w. if you are not hitting those marks, efficiency will drop, therefore consuming a bit more power | Report abuse Ask the community Publish Tom's Hardware>Forum>Components>Power Suppy Question> Related ressources: ForumPower Suppy question ForumQuestion re power suppy ForumPower suppy question ForumSilly Case/ Power Suppy Question Forumpower suppy connection question ForumPower suppy / mainboard question ForumUncertainty of power suppy and new graphic card ForumCase Power Suppy recommendations (i52500k/Z68XP-UD3/GTX450) ForumPower Suppy ? I'm a PC noob. ForumPower Suppy Dips to 2.28V When Gaming Forumbuying new power suppy & mobo (conecting?) ForumPower Suppy Recommendation ForumPower Suppy the problem..? ForumPOWER SUPPY AND MOTHERBOARDS FOR DELL OPTIPLEX ForumReplacing a power suppy Forum500w PSU ForumWhat power supply would be needed to run a radeon 6970 and an 8970? ForumFirst PC Build! How much suggested power? Forum[Solved] How much power do I need? Forum[Solved] Power supply fan stops spinning More resources Read discussions in other Components categories Power supplies Sound cards NICs Akasa Antec Cooler Master Cougar DeepCool Enermax !