title: How can the OS use all cores for my application?
body: <p>I have a COM written in Delphi 101 Berlin. And I write a script to call its API (just one API, single-threaded, and each takes around 1 minute to finish). </p>
  
  <p>I run the vbs file using cscript.exe (64 bit) (and I use the <a href="https://helloacm.com/the-simple-and-powerful-parallel-runner-for-windows-scripting-hosts/" rel="nofollow noreferrer">simple job runner here</a>), many copies (so there are many processes), at the same time.</p>
  
  <p>However, I have tested on many PC (Windows 10 Pro), and it is observed that only roughly 1 core is running despite that it many have many cores.</p>
  
  <p>For example, on my 2 CPUs (<a href="https://helloacm.com/review-hpz800-server-workstation-hp-z800-workstation-desktop-pc-tower-computer-powerhouse-2x-intel-xeon-x5650-48gb-ddr3-memory-2tb-hdd-1gb-nvidia-quadro/" rel="nofollow noreferrer">HPZ800 Intel Xeon X5650</a>, 6 cores each = 12 cores), only 1 core is being used. </p>
  
  <p>If some scripts exit early, then the rest CPU usage will be improved, but all together sum no more than 1 core.</p>
  
  <p>My question, is how to write code in order to benefit from multi cores?</p>
  
  <p><a href="https://i.stack.imgur.com/vRNGK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vRNGK.png" alt="enter image description here"></a></p>