Electromechanical machining (EMM) and Electrical Discharge Machining (EDM) are two distinct machining processes, each with its own advantages and limitations. The speed of machining depends on various factors, including the specific application, material, and machine parameters.
As of my last knowledge update in January 2022, I don't have specific comparative data on the machining speeds of EMM and EDM, and the efficiency can vary based on the particular requirements of a given task.
For the most accurate and up-to-date information, I recommend consulting reputable sources such as academic publications, industry journals, or the official websites of organizations specializing in machining technologies. Websites like the Society of Manufacturing Engineers (SME) or The American Society of Mechanical Engineers (ASME) may have relevant information or access to research articles comparing the efficiency of EMM and EDM.
Keep in mind that advancements in machining technologies are ongoing, and new research may have been published since my last update.