“Memory bandwidth to the CPUs has always been important. There were typically CPU cores that would wait for the data (if not in cache) from main memory. However, with the advanced capabilities of the Intel Xeon Phi processor, there are new concepts to understand and take advantage of.”
Prefetching Data for Intel Xeon Phi
“Prefetching on a coprocessor such as the Intel Xeon Phi coprocessor can be more important than on a main CPU such as the Intel Xeon CPUs. Since the cores on the Intel Xeon Phi coprocessor are in-order, they cannot hide memory latency as compared to an out-of-order CPU. In addition, since a coprocessor does not have an L3 cache, L2 misses must then access the slower memory subsystem.”
Why Modernize Code?
In order to speed up applications, a developer must learn to take advantage of the multiple threads, cores and sockets found on a single server or on a cluster. Just hoping for a faster CPU anymore won’t cut it.