Older ROM management tools cleaned up storage space by "trimming" unused data from game files. Because original DS systems could not read the DSi partition, early trimmers stripped the DSi binaries out completely to save file space.
Many users download "trimmed" ROMs to save SD card space. Trimming removes unnecessary data, but sometimes it mistakenly cuts out the DSi binaries, rendering the game unplayable in DSi-enhanced mode. The Dsi Binaries Are Missing Please Obtain A Clean Rom
Faster processing and improved performance compared to the original DS mode. Older ROM management tools cleaned up storage space