@qaz
You pretty much just look under your feet usually. Globally they get dumped in bulk on ebay, local platforms for p2p sales of used stuff also have them in most of the world.
@Cobrachicken

@Moonrise2473
That looks more like ARC problem, it can hold a large index of the filesystem if you give it enough room in ram, avoiding the need to seek thousands of files on a spinning disk, which takes time. HDDs are fine for sequential operations, Random IO, which is your usecase, is their biggest weakness.
@eleitl