The size of your set is heavily dependent on the file format you choose.
These are broad estimates because individual game sizes vary widely: many titles are <1 GB, while some are several GB (especially games with large assets or multiple language packs). Popular big titles (e.g., major 3D games, compilations) contribute disproportionately to totals. 3ds Complete Rom Set Size
You cannot fit a complete 2.5TB set on a standard USB stick or a laptop hard drive. Here is the realistic hardware you need. The size of your set is heavily dependent