Cosmic microwave background (CMB) radiation is a microwave frequency radiation thought to be left over from the big band. The CMB is from a time when the universe was approximately 300,000 years old. It has been observed to be about the same in all directions that we look at. Theoretical physicists perform complex calculations using the latest computer systems to test various models regarding the early universe compared to what is observed.
Modal is a cosmological statistical analysis package that can be optimized to take advantage of a high number of cores. The inner product computations with Modal can be run on the Intel Xeon Phi coprocessor. As a base, the entire simulation took about 6 hours on the Intel Xeon processor. Since the inner calculations are independent from each other, this lends to using the Intel Xeon Phi coprocessor.
One area of optimization is to look at loops which take a significant amount of processing time, and to first parallelize over outer loops. By adding threads to each loop, much larger utilization of the cores on the coprocessor can be utilized. With a range of optimizations, the performance of a subset of Modal showed performance gains of two orders of magnitude. One of the main optimization techniques involved understanding the numerical calculations very deeply, so that a math library routine could be replaced with hand written code that performed the exact function that was required. Through nested parallelism, applications can take advantage of both the host CPUs as well as coprocessors. It is also critical to understand the algorithms and numerical requirements to create optimized code.
Source: University of Cambridge, UK