title: What is coherent memory on GPU?
body: <p>I have stumbled not once into a term "non coherent" and "coherent" memory in the </p>
  
  <p><a href="https://renderdoc.org/vulkan-in-30-minutes.html">tech papers</a> related to graphics programming.I have been searching for a simple and clear explanation,but found mostly 'hardcore' papers of <a href="https://www.ece.ubc.ca/~aamodt/papers/isingh.hpca2013.pdf">this</a> type.I would be glad to receive layman's style answer on what  coherent memory actually is on GPU architectures and how it is compared to other (probably not-coherent) memory types. </p>