The Collider RF system is required to accelerate and store a 70 nlA DC proton beam from 2 TeV to 20 TeV. Various approaches have been studied as possible ways to accomplish this task. These include systems based on five-cell normal conducting cavities, single-cell normal conducting cavities, and single-cell superconducting cavities. This paper outlines the physics requirements that the system must meet and presents comparisons of the expected performance of various systems. Transient beam loading, injection error, power requirements, coupled bunch mode instabilities, etc. are considered.