In CRAY Macrotasking , tasks are assigned to processes when the code is written. Vectorization and Multitasking Programs can be both vectorized and multitasked. Vectorized code runs in vector mode on whichever processor runs it. Vector-parallel code consists of many vectorized tasks which may be executed in parallel by different processors. Vectorization reduces CPU time.
Parallel processing reduces wall-clock time.
The higher the level number, the smaller the size, or granularity of the task. Vector processing is level 4. Control parallelism of the various functional units is level 5. Hardware Support for Microtasking Cray Multiprocessor Architecture Shared registers are used to pass address and scalar information between processors, and for control among them. In general, fpp fails to recognize parallelism, so your program may not perform as well as expected.