title: Allocation time of square matrices
body: <p>I'm working on a project in C++ that needs to perform some pathfinding on a medium-sized adjacency matrix. These calculations will happen roughly once or twice a minute, and the typical values for V could be as large as 10,000. </p>
  
  <p>Computation time performance is my main concern, not memory performance.</p>
  
  <p>The graph here will always be symmetric, so I know some space can be saved by only using one triangle of the matrix, but still my question:</p>
  
  <p>How can I know at what point it will become speedier to retain this large array in memory and just zero all cells than to continually allocate, use, and deallocate the array? Are there mitigating factors here that I'm not aware of?</p>