Many players don't realize that "Preparing game data" also involves checking map synchronization with Blizzard's servers. If you play Ladder, the game validates that your local copy of a map matches the server hash.
This article is a deep dive into the technical underworld of StarCraft 2’s asset loading, cache management, and drive optimization. By the end, you won’t just wait for the game to load; you’ll have engineered a system where "Preparing game data" is a mere blink. starcraft 2 preparing game data extra quality