title: Approximate cost to access various caches and main memory?
body: <p>Can anyone give me the approximate time (in nanoseconds) to access L1, L2 and L3 caches, as well as main memory on Intel i7 processors?</p>
  
  <p>While this isn't specifically a programming question, knowing these kinds of speed details is neccessary for some low-latency programming challenges.  </p>