45 PSUs tested at very low loads: which one is the most efficient?
 

Recently when we've tested power supplies we regularly received comments about the fact that we test the efficiency of PSUs beginning at 200 watts. That's because the energy consumption of modern desktop PCs with Ivy Bridge or Haswell processors is typically a lot lower. It's a valid point, so we spent a lot of time in retesting many of the PSUs we've reviewed in recent months. This time we tested their efficiency at much lower load levels, of 22.5 watts, 50 watts and 100 watts. The results are definitely worth taking a closer look at.

http://uk.hardware.info/reviews/4683...most-efficient