title: Multiple threads and memory
body: <p>I read in the Visual C++ documentation that it is safe for multiple threads to read from the same object.</p>
  
  <p>My question is: how does a X86-64 CPU with multiple cores handle this?</p>
  
  <p>Say you have a 1 MB block of memory. Are different threads literally able to read the exact same data at the same time or do cores read one word at a time with only one core allowed to read a particular word at a time?</p>