Note:  CFCC Change Shared-Engine CF Default to  DYNDISP=THIN The CPs can run z/OS operating system images and CF images. For software charging  reasons, generally use only ICF processors to run CF images. Dynamic CF dispatching is shown in Figure 3-18. For more information about CF configurations, see  Coupling Facility Configuration Options ,  GF22-5042, and WP102400$^{16}$ Coupling Interrupt and Coupling Facility Performance. Flash Express is not supported on z15. This feature was replaced by IBM Z Virtual Flash  Memory (VFM), from z14. The Virtual Flash Memory feature code is 0643 on z15. Virtual Flash Memory (VFM) is an IBM solution to replace the external zFlash Express feature  with support that is based on main memory. The “storage class memory” that is provided  by Flash Express adapters is replaced with  memory allocated from main memory (VFM). 16 For more information about WP102400, see this web page:  http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP102400 3.10 Virtual Flash Memory 3.10.1 IBM Z Virtual Flash Memory overview 150  IBM z15 (8561) Technical Guide Figure 3-18 Dynamic CF dispatching options