Houdini 13.0 What’s new What's new in Houdini 13

Overview

OpenCL is a framework for writing programs that can run on various types of computing hardware, such as traditional CPUs and the Graphics Processing Units (GPUs) in video cards. Houdini’s Smoke and Pyro solvers use OpenCL to take advantage of extra hardware for more speed when available.

The new version of Intel’s OpenCL SDK includes support for taking advantage of general computing hardware in Intel CPUs on Windows. You can enable experimental support for this driver in Houdini using the steps below. This can give a general 1.5-3x – and sometimes much larger – speed advantage for large Pyro simulations on supported hardware.

The primary advantage of using OpenCL on the CPU is the ability to use all available RAM on the system, unlike the GPU which is limited to RAM on the video card. This allows running very large simulations under OpenCL, while still realizing increased performance through code vectorization and more efficient memory access.

Note

Support for this version of the library is experimental in Houdini 13.0. It is not a polished, finished feature, but is available if you want to try it.

How to set up the driver under Windows

  • Download the Runtime Only for Windows package from the Intel website.

  • Install the runtime driver by executing the downloaded file. During installation you can ignore any references to the Intel® Manycore Platform Software Stack, which are only relevant to the Xeon Phi coprocessor which has not been tested with Houdini.

  • Set the proper environment variables to indicate Houdini should use the OpenCL CPU Driver, as described here. You should set the following variable:

    HOUDINI_OCL_DEVICETYPE=CPU

    If you have installed another CPU driver from another vendor such as AMD, also set the following:

    HOUDINI_OCL_VENDOR=Intel(R) Corporation

  • Verify that Houdini is using the Intel OpenCL driver. Launch Houdini and choose About Houdini from the Help menu. Then click on Show Details and look for the OpenCL driver information about halfway down. The beginning of the output should be similar to the following

OpenCL Platform           Intel(R) OpenCL
Platform Vendor           Intel(R) Corporation
Platform Version          OpenCL 1.2 
OpenCL Device             Intel(R) Xeon(R) CPU           X5650  @ 2.67GHz
OpenCL Type               CPU
Device Version            OpenCL 1.2 (Build 76921)
  • When running Smoke or Pyro simulations, enable Use OpenCL on the Advanced tab.