Publications

Optimization of Real-Time Object Detection on Intel® Xeon® Scalable Processors

November 11, 2017

This publication demonstrates the process of optimizing an object detection inference workload on and Intel® Xeon® Scalable processor using TensorFlow. This project pursues two objectives: Achieve object detection with real-time throughput (frame rate) and low latency Minimize the required computational resources In this case study, a model described in the “You Only Look Once” (YOLO) project is used for object detection. The model consists of two components: a convolutional neural network and a post-processing pipeline. In this work, the original Darknet model is converted to a TensorFlow model. First, the convolutional neural network is optimized for inference. Then array programming with NumPy and TensorFlow is implemented for the post-processing pipeline. Finally, environment variables and other configuration parameters are tuned to maximize the computational performance. With these optimizations, real-time object detection is achieved while using a fraction of the available processing power of an Intel Xeon Scalable processor-based system. [...]

A Performance-Based Comparison of C/C++ Compilers

November 11, 2017

This paper reports a performance-based comparison of six state-of-the-art C/C++ compilers: AOCC, Clang, G++, Intel C++ compiler, PGC++, and Zapcc. We measure two aspects of the compilers’ performance: The speed of compiled C/C++ code parallelized with OpenMP 4.x directives for multi-threading and vectorization. The compilation time for large projects with heavy C++ templating. In addition to measuring the performance, we interpret the results by examining the assembly instructions produced by each compiler. The tests are performed on an Intel Xeon Platinum processor featuring the Skylake architecture with AVX-512 vector instructions.  Colfax_Compiler_Comparison.pdf (562 KB) — this file is available only to registered users. Register or Log In. Table of Contents 1. The Importance of a Good Compiler 2. Testing Methodology 2.1. Meet the Compilers 2.2. Target Architecture 2.3. Computational Kernels 2.4. Compilation Time 2.5. Test Details 2.6. Test Platform 2.7. Code Analysis 3. Results 3.1. Performance of Compiled Code 3.2. Compilation Speed 4. Summary Appendix A. LU [...]

A Survey and Benchmarks of Intel® Xeon® Gold and Platinum Processors

November 7, 2017

This paper provides quantitative guidelines and performance estimates for choosing a processor among the Platinum and Gold groups of the Intel Xeon Scalable family (formerly Skylake). The performance estimates are based on detailed technical specifications of the processors, including the efficiency of the Intel Turbo Boost technology. The achievable performance metrics are experimentally validated on several processor models with synthetic workloads. The best choice of the processor must take into account the nature of the application for which the processor is intended: multi-threading or multi-processing efficiency, support for vectorization, and dependence on memory bandwidth.  Colfax-Xeon-Scalable.pdf (334 KB) — this file is available only to registered users. Register or Log In. Table of Contents 1. Which Xeon is Right for You? 2. CPU Comparison for Different Workloads 3. Processor Choice Recommendations 4. Silver and Bronze Models 5. Large Memory, Integrated Fabric, Thermal Optimization Why are some sections grayed out? You are viewing an abridged version of this [...]

Capabilities of Intel® AVX-512 in Intel® Xeon® Scalable Processors (Skylake)

September 19, 2017

This paper reviews the Intel® Advanced Vector Extensions 512 (Intel® AVX-512) instruction set and answers two critical questions: How do Intel® Xeon® Scalable processors based on the Skylake architecture (2017) compare to their predecessors based on Broadwell due to AVX-512? How are Intel Xeon processors based on Skylake different from their alternative, Intel® Xeon Phi™ processors with the Knights Landing architecture, which also feature AVX-512? We address these questions from the programmer’s perspective by demonstrating C language code of microkernels benefitting from AVX-512. For each example, we dig deeper and analyze the compilation practices, resultant assembly, and optimization reports. In addition to code studies, the paper contains performance measurements for a synthetic benchmark with guidelines on estimating peak performance. In conclusion, we outline the workloads and application domains that can benefit from the new features of AVX-512 instructions.  Colfax-SKL-AVX512-Guide.pdf (524 KB) — this file is available only to registered users. [...]

Optimization of Hamerly’s K-Means Clustering Algorithm: CFXKMeans Library

July 21, 2017

This publication describes the application of performance optimizations techniques to Hamerly’s K-means clustering algorithm. Starting with an unoptimized implementation of the algorithm, we discuss: Thread scheduling Reduction patterns SIMD reduction Unroll and jam Presented optimizations aggregate to 85.6x speedup compared to the original unoptimized implementation. Resulting implementation is packaged into a library named CFXKMeans with interfaces for C/C++ and Python. The Python interface is benchmarked using the MNIST 784 data set. The result for K=64 is compared to the performance of K-means clustering implementation in a popular machine learning framework, scikit-learn, from the Intel distribution for Python. CFXKMeans performed our benchmark tests faster than scikit-learn by a factor of 4.68x on an Intel Xeon processor E5-2699 v4 and 5.54x on an Intel Xeon Phi 7250 processor. The CFXKMeans library has C/C++ and Python API and is available under the MIT license at https://github.com/ColfaxResearch/CFXKMeans.  Colfax-Kmeans-Clustering-Optimization.pdf (365 KB) [...]

HPLinpack Benchmark on Intel Xeon Phi Processor Family x200 with Intel Omni-Path Fabric 100

July 10, 2017

We report the performance and a simplified tuning methodology of the HPLinpack benchmark on a cluster of Intel Xeon Phi processors 7250 with an Intel Omni-Path Fabric 100 Series interconnect. Our benchmarks are taken on the Colfax Cluster, a state-of-the-art computing resource open to the public for benchmarking and code validation. The paper provides recipes that may be used to reproduce our results in environments similar to this cluster.  Colfax-HPL-Intel-Xeon-Phi-x200-and-Intel-Omni-Path-100.pdf (130 KB) — this file is available only to registered users. Register or Log In. Table of Contents Section 1. HPLinpack Benchmark Algorithm HPL Configuration File Section 2. System Configuration Intel Architecture Colfax Cluster Section 3. Results Recipe Performance Impact of System Configuration Section 4. Summary Section 1. HPLinpack Benchmark The HPLinpack benchmark generates and solves on distributed-memory computers a large dense system of linear algebraic equations with random coefficients. The benchmark exercises the floating-point arithmetic units, the memory subsystem, [...]

FALCON Library: Fast Image Convolution in Neural Networks on Intel Architecture

November 9, 2016

We describe FALCON, an original open-source implementation of image convolution with a 3×3 filter based on Winograd’s minimal filtering algorithm. Compared to direct convolution, Winograd’s algorithm reduces the number of arithmetic operations at the cost of complicating the memory access pattern. This study is carried out in the context of image analysis in convolutional neural networks. Our implementation combines C language code with BLAS function calls for general matrix-matrix multiplication. The code is optimized for Intel Xeon Phi processors x200 (formerly Knights Landing) with Intel Math Kernel Library (MKL) used for BLAS call to the SGEMM function. To test the performance of FALCON in the context of machine learning, we benchmarked it for a set of image and filter sizes corresponding to the VGG Net architecture. In this test, FALCON achieves 10% greater overall performance than convolution from DNN primitives in Intel MKL. However, for some layers, FALCON is faster than MKL by 1.5x, but for other layers slower by as much as 4x. This indicates a possibility of a [...]

Machine Learning on 2nd Generation Intel® Xeon Phi™ Processors: Image Captioning with NeuralTalk2, Torch

June 20, 2016

  In this case study, we describe a proof-of-concept implementation of a highly optimized machine learning application for Intel Architecture. Our results demonstrate the capabilities of Intel Architecture, particularly the 2nd generation Intel Xeon Phi processors (formerly codenamed Knights Landing), in the machine learning domain. Download as PDF:  Colfax-NeuralTalk2-Summary.pdf (814 KB) — this file is available only to registered users. Register or Log In. or read online below. Code: see our branch of NeuralTalk2 for instructions on reproducing our results (in Readme.md). It uses our optimized branch of Torch to run efficiently on Intel architecture. See also: colfaxresearch.com/get-ready-for-intel-knights-landing-3-papers/ 1. Case Study It is common in the machine learning (ML) domain to see applications implemented with the use of frameworks and libraries such as Torch, Caffe, TensorFlow, and similar. This approach allows the computer scientist to focus on the learning algorithm, leaving the details of performance optimization to the framework. Similarly, the ML [...]

Intel® Python* on 2nd Generation Intel® Xeon Phi™ Processors: Out-of-the-Box Performance

June 20, 2016

This paper reports on the value and performance for computational applications of the Intel® distribution for Python* 2017 Beta on 2nd generation Intel® Xeon Phi™ processors (formerly codenamed Knights Landing). Benchmarks of LU decomposition, Cholesky decomposition, singular value decomposition and double precision general matrix-matrix multiplication routines in the SciPy and NumPy libraries are presented, and tuning methodology for use with high-bandwidth memory (HBM) is laid out. Download as PDF:  Colfax-Intel-Python.pdf (1 MB) — this file is available only to registered users. Register or Log In. or read online below. Code: coming soon, check back later. See also: colfaxresearch.com/get-ready-for-intel-knights-landing-3-papers/ 1. A Case for Python in Computing Python is a popular scripting language in computational applications. Empowered with the fundamental tools for scientific computing, NumPy and SciPy libraries, Python applications can express in brief and convenient form basic linear algebra subroutines (BLAS) and linear algebra package (LAPACK) [...]

Get Ready for Intel’s Knights Landing (KNL) – 3 papers

May 11, 2016

2nd generation Intel Xeon Phi processors code-named Knights Landing (KNL) are expected to provide up to 3X higher performance than the 1st generation. With on-board high-bandwidth memory and optional integrated high-speed fabric—plus the availability of socket form-factor — these powerful components will transform the fundamental building block of technical computing. Download three essential publications on new features in Knights Landing Processors: Automatic Vectorization with Intel AVX-512 Instructions in KNL In this document, we focus on the new vector instruction set introduced in Knights Landing processors, Intel® Advanced Vector Extensions 512 (Intel® AVX-512). The discussion includes: Introduction to vector instructions in general, The structure and specifics of AVX-512, and Practical usage tips: checking if a processor has support for various features, compilation process and compiler arguments, pros and cons of explicit and automatic vectorization, using the Intel® C++ Compiler and the GNU Compiler Collection. Download PDF Read Online Clustering Modes in Knights [...]
1 2 3 5