I haven't a clue what you mean by lanes? I've never heard that with respect to RAM before. The reason more RAM can speed up your machine is that whatever you are currently working on is loaded into RAM. RAM provides the fastest I/O between the processor. So if the program is calling for a piece of data and its currently in RAM, then retrieving that data will be fast. If it has to pull from the hard drive, that will slow it down. If it has to pull from a different storage that can slow it down even more.
Bottlenecks can occur in various places, not just the Internet connection.