Memory wall https://koputokiryo.com/%e3%80%90%e8%8b%b1%e5%ad%97%e6%96%b0%e8%81%9e%e3%82%92%e8%aa%ad%e3%82%80%ef%bc%81%e3%80%91%e3%82%bc%e3%83%ac%e3%83%b3%e3%82%b9%e3%82%ad%e3%83%bc%e5%a4%a7%e7%b5%b1%e9%a0%98%e3%81%af%e6%88%a6%e4%ba%89/memory-wall/