Acceleration must be off if you want to get the same sensitivity.
I've checked a iMac 5k now, and from what I can tell the sensitivity changes with the display scaling. The default for the 5k was 200% (2560x1440), while the highest was 160% (3200x1800). I don't know how it scales on different systems, and what the other scaling options are. But if you find out this is what you need to match it with Windows.
By multiplier I mean the relation between the resolution. So for instance if you're using 1000 DPI in Windows is with 1920x1080 and MacOS is 3200x1800, you do 3200/1920*1000=1667 DPI in MacOS.