The next generation computing systems are focusing on parallel computing to solve the problem in fast and high speed using parallel programming concepts. The running time of any complex algorithm or applications can be improved by running more than one task at the same time with multiple processors concurrently. Here the performance improvement is measured in terms of increase in the number of cores per machine and is analyzed for better Energy Efficient optimal work load balance. In this paper we investigate the review and literature survey of parallel computers for future improvements. We aim to present the theoretical and technical terminologies for parallel computing. The focus here is the process of comparative analysis of single core and multicore systems to run an application program for faster execution time and optimize the scheduler for better performance.