I was working with a client today trying to talk about the Distributed Cache in SharePoint 2013 and I found this great article by Sean McDonough (spmcdonough).

High points:
  1. Distributed Cache replaces the older Cache mechanisms in SharePoint 2007 and 2010 and adds some security stuff as well
  2. Runs on the AppFabric Cache model
  3. Uses 10% of the RAM on the sever by default.  Watch memory utilization because if the host is memory starved, the cache will stop working
  4. Don’t run it on servers that run Search, Excel Calculation, SQL Sever, Project Server
  5. You don’t HAVE to run it…but it will make your users experience better if you set it up correctly.

Kudos to Sean for a great article and I hope that your Distibuted Cache is always fast!