MODE-3 Coprocessor Lab-overview :
hyPACK-2013 : Mode-3 ( Coprocessors) Power & Performance

Topics dealing with all practical and experimental aspects of various programming paradigms are considered on measurement of power consumption on Intel Xeon Phi Coprocessors for application kernels in order to achieve the best sustained performance with reduction in power consumption. Participants will get an opportunity to walk-through and execute some of the programs related to measurement of Power Consumption as well as performance of Benchmarks on Intel Xeon Phi Coprocessor Systems. in Mode-3 of this workshop. Understanding Intel's MIC architecture and programming models for the Intel Xeon Phi coprocessor may enable programmers to achieve good performance of their applications. Important tools and utilities used to measure power consumption for application kernels in hyPACK-2013 workshop are given below.

Intel Xeon Phi Coprocessor provides on-line tool micsmc to measure MIC related tasks. micsmc : Provides a GUI to perform many MIC related tasks. The available tasks include retrieving device and driver info, and monitoring device performance, temperatures, and core usage. Visit http://software.intel.com/mic-developer

MIC Platform Status Panel (micsmc(1)) is a graphical tool designed to facilitate the administration of Inte MIC devices. (micsmc(1)) can function in two modes: GUI mode and command-line (CLI) mode. GUI mode provides continuously updated information regarding MIC core utilization, core temperature, memory used, and power usage statistics. CLI mode produces similar information, but is a one-shot operation which allows for use in scripting applications. By design, MicSmcoperates on all cards in the system. GUI mode provides both system-level and per-card views, while CLI mode always operates on all cards.

(micsmc(1)) can also be used to perform more advanced functions: viewing error logs, monitoring and connecting to MIC devices, viewing/rotating logs, and changing individual card settings such as enabling ECC, power states, and Turbo Modes on K1OM devices. For more information regarding the usage of micsmc, please refer to The Platform Status Panel User Guide. MICSMC can be invoked in command-line mode with different arguments to indicate the results in the output of average and per core utilization levels for each available board in the system and some of these features are given below.

• Results in the output of clock frequency and power levels for each available board in the system.
• Results in the output of general system info.
• Results in the output of memory utilization data.
• Results in the output of temperature levels for each available board in the system.
• To measure load on given system

The Intelligent Platform Management Interface (IPMI) specification defines standards for monitoring server hardware characteristics such as system temperatures, voltages, and power supplies. IPMItool, an open source utility for managing and configuring IPMI-compliant devices, enables administrators to monitor, log, recover, inventory, and control hardware in Multi-Core servers through a simple baseboard management controller (BMC) command-line interface (CLI). IPMI 2.0 specification available at
http://www.intel.com/content/www/us/en/servers/ipmi/ipmi-home.html

On a Message Passing Cluster, the calculation of power consumption on host and the Intel Xeon Co-processor using approriate Programming (MPI, OpenMP, Pthreads, OpenCL) is required. The calculated power consumption out of coprocessor, data transfer from host to device & device to host, IO operations as well as initial programming environment will contribute to the total power consumption of an application.

Figure 1. Typical Pthread Model for Calculation of Power Consumption on a system

Figure 1 explains the flow of completion of jobs in which two Pthreads are used. One thread executes job on device and another thread probes the external power-off meter and gathers the reported power values. Also, one thread works on Xeon multi-coprocessor and records the power values for the entire system. Multiple threads can be used to bind multiple accelerators and coprocessors to record the power consumed and master thread gathers the data and display on the portal. The resolution of power meter is in watts. On Intel Xeon Phi Coprocessor, the micsmc and ipmi are used to measure real-time power consumption of BLAS kernels and PDE solver. We analyzed the performance and real-time power consumption of two fundamental linear algebra algorithms - DGEMM using above power utilities in on-line and off-line mode.

The power analyzer electricity watt meter is also used to measure the reported power values. The Watt's Up power meter is an external measurement device that is plugged into the system and it provides various measurements via a USB serial connection. The power metrics collected include average power, voltage, current, and various others. Energy can be derived based on the average power and time. The results are system-wide and low resolution, with updates only once a second. Limited memory exists on power-meter and hence the reported power values for computational performed are collected. Another thread reads the data on a regular basis, and then returns overall values when an instrumented program requests it.