Well what to say about the G.Skill ECO. On one hand there is simply no voltage scaling possible on our sample. It refuses to go higher with anything over 1.5 V. G.Skill aims these at the user who want to run their system as power efficient as possible, but I do not know what kind of a difference these will make in total. Sure a 0.3V difference to other P55 or X58 kits out there is significant by itself, but when all the components are tallied up, that may become miniscule. For those aiming to run the most efficient CPUs, GPUs, boards and then going the extra mile to undervolt their CPU - this memory is for you. Even though it lacks good voltage scaling, the bump in maximum speed with each adjustement in latency is there and the memory even runs at 2000 MHz at CL9 with 1.5 V, still below the mainstream kits at these settings which require 1.65 V. That said, the G.Skill ECO 1600 MHz CL7-8-7 1.35V are perfect for those focusing on that last number and not being concerned with pushing it higher. But, at this price point, it may even be a great option for everyone else as well.