Memory and communication
- Most communication in a computer is carried out in chunks, blocks of bytes of data that move together
- In the memory hierarchy, data moves between memory and cache, and between different levels of cache, in groups called lines
- Lines are typically 64-128 bytes, or 8-16 double precision words
- Even if you do not use the data, it is moved and occupies space in the cache
- This performance feature is not captured in most programming languages