Buffering writes is fine if you're ok with losing your data. For some applications that's acceptable, but when I'm writing to disk, it's because I want persiste

Buffering writes is fine if you're ok with losing your data. For some applications that's acceptable, but when I'm writing to disk, it's because I want persistence. "It'll get flushed to disk at some point as long as power doesn't go out" is hardly that.