title: Writing files locally vs. remote file system?
body: <p>My question is about remote files systems on Windows.</p>
  
  <p>Suppose you have workstation X which has access to files systems on the network - say - <code>\\ServerY\MYDir\</code>.</p>
  
  <p>Imagine a scenario that you have two simultaneous threads on X.</p>
  
  <ol>
  <li>Thread 1 is writing a file to local hard drive directory in X - <code>C:\MYDir\</code>.</li>
  <li>Thread 2 is writing to the remote file in <code>\\ServerY\MYDir\</code>.</li>
  </ol>
  
  <p>I want to know are these two IO operations actually independent, i.e is thread 1 only using hard disk controller of X and thread 2 only using the network and passing all data to Server on the wire, where is is actually written to the hard drive on serverY.</p>
  
  <p>Or</p>
  
  <p>Is thread 2 also making some local cache data in X (and hence using the hard disk controller on X). In this case the IO operations of thread 2 may interfere in operation of thread1 which may lead to possible performance loss.</p>
  
  <p>Basically - will there be any gain in doing writes on a local file and that on a remote file in parallel?</p>
  
  <p><em>My question is specific to remote file system supported by windows like Microsoft Networks or NFS</em></p>