eWEEK at 30: Multicore CPUs Keep Chip Makers in Step With Moore's Law
In the PC space, it's not as common for applications to use four or more cores, and it's even less so in smartphones, he said. Still, the future track is for even more cores for chips that run in all computing devices, Bajwa said. In the high-performance computing space, organizations run highly parallel applications that can take advantage not only of processors with large numbers of cores, but also GPU accelerators that can contain hundreds of cores and can be used to run workloads that have been offloaded from the main processor. In addition, Intel's x86-based Xeon Phi coprocessors, which run in systems with Xeon chips and essentially have the same job as the GPU accelerators, hold more than 60 cores. Intel's upcoming 14-nanometer "Knights Landing" Xeon Phi chips not only will be able to be used as coprocessors, but also as the primary processors, according to Intel officials. The number of cores will continue growing in the mobile space as well. Most recently, ARM—which designs systems-on-a-chip (SoCs) and licenses those designs to manufacturers like Samsung and Qualcomm—introduced its big.Little architecture in 2011 as a way of addressing the sometimes conflicting user demands for more performance and longer battery life by pairing low-power Cortex-A7 cores with higher performing cores on the same SoC. The Cortex-A7 is used for basic tasks, while the larger cores are used with more compute-intensive jobs.But as those cores are being added, there are challenges that will have to be dealt with, Intel's Bajwa said. One of the biggest challenges for chip engineers will be keeping balance in the processors. As more cores are added, the chips will be able to process and execute increasingly large numbers of workloads and data. However, engineers also have to ensure that there continues to be enough bandwidth to the memory and the I/O to ensure that applications can take full advantage of all the cores. Heat also will continue to be a challenge, as will power management, he said, bringing the industry back to the problems that the multicore design dealt with a decade ago. "The trend is toward more and more compute with more threads and … with more cores," Bajwa said. "My sense is the cores are going to continue to grow over time."
ARM in February announced its upcoming Cortex-A17 design, which will begin appearing in devices in 2015. The same day, MediaTek announced its upcoming MT6595 SoC design that will leverage the Cortex-A17 in a big.Little configuration for an eight-core mobile chip that will combine four Cortex-A17 cores with four Cortex-A7 cores.