We present a comprehensive study on multigigahertz repetition rate Nd:YVO/sub 4/ lasers, passively mode-locked with semiconductor saturable absorber mirrors. A brief review of Q-switching instabilities with special emphasis on high repetition rate is given. We then present basic design guidelines, and experimentally show that one can push the pulse repetition rate of a Nd: YVO/sub 4/ laser up to 157 GHz, reaching the fundamental limit to the repetition rate which is given by the pulse duration and thus by the amplification bandwidth. We also demonstrate an air-cooled diode-pumped 10-GHz Nd: YVO/sub 4/ laser with 2.1-W average output power and 13% electrical-to-optical efficiency, showing the potential of solid-state lasers generating multiwatt, multigigahertz pulse trains with high efficiency.