What is the difference between these two types of memory. The specifications seem identical:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148144
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148076
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148144
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148076