I have an early 2011 MacBook Pro, and I want to upgrade it to 8GB of RAM. Right now, these are my two choices: http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=8C4DD5E1A5CA7304 http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=4C535AB1A5CA7304 As far as I can tell, the only difference between the two is that the first one uses 1.5V and the second one uses 1.35V. My question is: what difference will that make in my experience using the computer? I assume that the second one will use less energy, and therefore increase battery life. But am I right? And if so, will it work just as fast? Crucial recommends the 1.5V version, but they may just be trying to clear out old stock. Any advice you can give me is appreciated. Thanks!