IgorsLAB published Performance increase for gamers: Memory with single-rank, dual-rank and quad-rank explained and compared A quote from the article:

The fact that you should use your RAM at least in dual-channel if possible has fortunately become widely accepted in the industry today. However, unlike channels, ranks are still talked about very rarely, if at all. Many publications, some of them very well known, prefer instead to talk about “sticks” or modules affecting performance, which is not only wrong but also causes confusion and disinformation in the community. Today we want to examine some of these “myths” and correct them if necessary.

  Performance increase for gamers: Memory with single-rank, dual-rank and quad-rank explained and compared