How important is RAM voltage? I realize they should probably match, but should I go for a lower or higher voltage....I assume lower is better as most PC related power usage issues, lower power is better, but I want to make sure. And second, I'm building a gaming PC and wonder how much difference a cas latency of 9 rather than 6 is?
As for voltage, it really depends the CPU you purchase to a point. The new Intel chips need to have RAM voltage of 1.65V or less, so for them lower is better to give your overclocking room with voltage increases. As for AMD, it is really an issue, as they don't have that requirement.
As for today's market, it pretty standard to be looking for DDR3 at 1.65V or less with 1.5V being ideal, as motherboards default to 1.5V.
As for the latency... the article holds true that lower is better but in the "real world", there is little noticeable difference.