Real is real scaled particle speed...I tried to play with speed settings but even on normal or slowest the wind on app moves at least 5 times faster . That means that if wind speed is 20kmh , the app shows like moving with 100kmh at least... On fast setting the 20kmh animate like 1000... PLZ WINDY BUT THAT REAL SPEED BUTTON ON, AND THANX FOR GREAT JOB UDOING FOR US...I LL DONATE ONE WAY OR ANOTHER BUT MORE WITH THE BUTTON ON