Despite being solid state, SD cards have horrible random read and write speeds, worse even than HDDs. They're made for storing media from cameras, so it doesn't

Despite being solid state, SD cards have horrible random read and write speeds, worse even than HDDs. They're made for storing media from cameras, so it doesn't matter. Maybe RPis do OK cause they just load the system once, maybe even sequentially. I also keep a card in my MBP. It takes forever to write directories, but it's good enough to store Xcode etc only cause the RAM caches things. Torrenting Ubuntu onto it was unusably slow. I expect it'd be unusable as single-level storage.