Array-oriented programming. Add all velocities to all positions, etc
How do you explicitly tell the CPU to fetch the next batch of data before you start processing the current batch so that the cache is hot when you need it? I imagine there are instructions for that.
There is a prefetch instruction but you also don't need to in obvious loops like that because the CPU has hardware to detect sequential access patterns. IIRC one test showed a CPU could prefetch up to 11 interleaved sequential access patterns with different strides.