A parallel computer is a multiprocessor system with MIMD computer architecture, Multiple Instruction Multiple Data (MIMD), whose processors run a program simultaneously.
Parallel computers operate on the principle of workload sharing and are ideal for processing large amounts of data. They are used, among other things, in high-performancecomputers( HPC). Each functional unit of a parallel computer processes a program section in parallel. Task distribution and synchronization are important aspects for computing performance.
Parallel processing can be performed by "n" processors, with the computing speed decreasing with the number of processors. Theoretically, the computing time with n processors is only 1/n.
There is another computer architecture in which several instructions are processed simultaneously in parallel and which could replace the classic Von Neumann computer: Explicit Multi-Threading(XMT), a concept developed by the University of Maryland in which the tasks for the individual processors of the multi-core process ors are not distributed by the operating system, but hardware-wise by a processor.