Hi I have a 500 watt PSU , does it consumer more energy than say a 350 watt or only the energy its required to supply? or does a 500 watt use 500 watts all the time and the 350 watt , 350 watts all the time ??? Thanks Woody uk
The more the computer needs the more it can supply up to the maximum, if its a 350 watt power supply thats its maximum. But its the computer that decides how much power it needs from the power supply. A 500 watt power unit uses no more than a 350 watt unit if they are connected to the same PC.
Erm,I would just like to mention the PSU Review I read recently where part of the judging of which PSU was best included its efficiency.
"An area of increasing interest is the overall efficiency of the PSU itself, or, in other words, how much power it requires from the mains to produce the requested load. Efficiency is very important because, like an internal combustion engine, any wasted energy is dissipated as heat, which the cooling system has to get rid of before it reduces the effectiveness of the electronic components inside the PSU, or catches fire. This means that a less efficient PSU will require a more powerful and noisy cooling system. An efficient PSU, on the other hand, will run cooler and draw less power, so it will help to keep your electricity bill down. The ATX spec cites that at 50 per cent load, efficiency must be 72 per cent or higher, and at 100 per cent load, 70 per cent or higher. The efficiency figures are also quoted on the test sheet.
It's also important to test the efficiency of the Power Factor Correction (PFC) circuitry of a PSU. The PFC distributes the power between the different rails, so an inefficient PFC means that a lower fraction of the PSU's available power actually gets distributed across each rail. And because components drain different amounts of power on different rails over time, it's very important for a PSU to have good PFC. The PFC of the generic 600W PSU is also listed at the end of each test on the Test Sheet."