I have been running both side by side, for years, Ignoring the lack of adequate graphics cards available for the Mac (Which affects Octane, Luxcore, Iray and Superfly/Cycles), the Mac is significantly slower than a Windows machine. You simply can't get the same processors, the graphics cards are the mobile variety, and generally the Mac is normally, about a year, or more, behind the hardware available for Windows. Further the fastest Intel processors, simply are not available for the Mac due to cooling concerns.