It's apples and oranges (or chalk and cheese, depending on where you live): RPM versus RCF.

Abstract

At Autophagy we request that authors express centrifugal values as relative centrifugal force (RCF) or g-force as opposed to revolutions per minute (RPM). This is not an arbitrary decision but to understand the reason we need to provide a brief explanation of the difference between these two terms and, yes, there is a difference. Hence, it is annoying when during the editing process we request that an author convert a stated value such as "12,000 RPM" to "×g" and they simply return the paper with "12,000 ×g." The problem is that "12,000 RPM" is not equivalent to "12,000 ×g."