I don't understand the "Multi-core effects" one. Surely the linear memory scans in c[i] = a[i] + b[i] will result in cache prefetch and thus be limited by memo

I don't understand the "Multi-core effects" one. Surely the linear memory scans in c[i] = a[i] + b[i] will result in cache prefetch and thus be limited by memory bus bandwidth and not cache size?