Performance

  The Class(y) kernel is written in optimized C and assembler code, and it
  executes as fast as it is possible to do in the Clipper environment.

  As you know, Clipper is a sophisticated and powerful application
  development language, which in many ways pushes DOS past its limits - for
  example, by making use of virtual memory to circumvent the 640K
  limitation.

  As a result, Clipper and Class(y) will perform best if given the resources
  they need.

  An important performance issue is expanded memory (EMS). At least a
  megabyte of expanded memory should be available to Clipper/Class(y)
  applications. In larger applications, two or more megabytes of EMS may be
  needed for optimal performance. Otherwise, Clipper may be forced to swap
  virtual memory pages to disk, resulting in a dramatic performance drop.

  Applications should, of course, be overlayed as efficiently as possible,
  so that as much memory as possible is available for virtual memory paging
  and other purposes. Link options which increase the root size of an
  application, such as incremental linking, should be avoided if memory or
  performance is at a premium. Symbol table compaction should be enabled
  when linking such systems.