Intel to Boost Performance of Single-Threaded Software on Mullti-Core Processors

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The opposite of hyper-threading?

Intel to Use Multi-Core Chips to Boost Performance of Single-Threaded Apps
[05/19/2010 11:55 PM]
by Anton Shilov

The modern trend of microprocessors’ development is focused around creation of devices with as many cores as possible. However, there are algorithms that cannot benefit from many-core architectures or multi-threading execution. In order to boost performance of single-threaded applications on multi-core microprocessors, Intel Corp. recently outlined the technology called “Anaphase”.

Researchers from Intel Labs Barcelona have developed “Anaphase” technology, which is a novel hardware/software hybrid approach to leverage multiple cores in order to improve single-thread performance on multi-core processors. This research focuses on different speculative techniques to automatically partition single thread applications to be processed on multiple cores.

The proposed technique features a set of novel hardware mechanisms that support the execution of threads generated at compile time. These threads result from a fine-grain speculative decomposition of the original application and they are executed under a modified multi-core system that includes: mechanisms to support multiple versions; mechanisms to detect violations among threads; mechanisms to reconstruct the original sequential order; and mechanisms to checkpoint the architectural state and recovery to handle misspeculations. On the hardware side, a new unit called “Inter-Core Memory Coherency Module” (ICMC) could be integrated into the die of future processors.

According to Intel, the proposed hardware/software scheme outperforms previous hardware-only schemes to implement the idea of combining cores for executing single-thread applications in a multi-core design by more than 10% on average on Spec2006 for all configurations. Moreover, single-thread performance is improved by 41% on average when the proposed scheme is used on a so-called “tiny-core” (Intel did not reveal, what tiny-core actually is, but it may potentially be a part of the company’s SSC 48-core processor), and up to 2.6 times for some selected applications.

At the present Anaphase is a research project and the Intel Labs Barcelona researchers are looking into ways how to potentially integrate this technology into future processor designs.

Considering that Intel is working on numerous many-core designs, including Larrabee x86 graphics processor and 48-core supercomputer on a chip (SCC) prototype, the ICMC may indeed be a useful piece of hardware. In fact, not only for Intel. Both ATI, graphics business unit of Advanced Micro Devices, and Nvidia Corp. are working hard to implement their many-core graphics processing units (GPUs) into various high-performance computing (HPC) segments. Although raw horsepower is more important for HPC that performance of single-threaded apps, as general purpose processing on GPUs (GPGPU) becomes more popular on different markets, hardware/software tricks to speed up single-threaded algorithms may become necessary.

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