Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

> Where memory latency hurts for us is ISRs and context switches. The hit rate is temporarily very low, and as you mentioned the IPC suffers greatly.

While that is true, that is infrequent and having those memory accesses take 151 cycles instead of 150 cycles is not going to make much difference. Note that those are ballpark figures.



For DDR4 it's 17 vs 16 memory cycles for the data burst phase.


If you measure memory access time in CPU cycles, you would see that 150 cycles is the ballpark. 16 cycles would be closer to L2 cache.




Consider applying for YC's Fall 2026 batch! Applications are open till July 27.

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: