Modern microprocessors feature turbo mechanisms that adjust the clock frequency dynamically so as to maximize processor performance under power and temperature limits. However, the documentation for commercial chips rarely provides more than a superficial description of how turbo works. This paper highlights certains aspects of turbo that are not well known outside the industry and that distinguish it from dynamic thermal management. A plausible open-source turbo is proposed and described, extrapolating from the scarce and sparse information that has been disclosed so far.