I took a look at the code to summarize for those curious - it looks like all the production buildings plus labs and miners have speed x3. Loaders enabled, Inserters + trains + bots + belts(?) sped up as well. It looks like energy production from steam engines and solar was also increased. Gun + Laser turrets were also changed, and most everything mentioned here had its energy changed as well (assumedly increased by 3 to match the speed). Also, player can smelt ores by hand
To MasterManiaZ -- the description was updated in info.json but here on the website we still have the older one which you'll need to update as well - "Accelerates (3x) multi aspects of the game to reach end game sooner and have fun".
