For instance, among all the 300W power supplies, the weight ranged from 2.15 to 3.8lb, a 1.65lb difference. The lightest one is only 57% of the heaviest in weight. Among the 250W, the weight ranged from 1.7 to 3.1lb, a 1.4lb gap. The heaviest one is 82% heavier than the lightest one.
