Documentation

Differences Between the Working Modes of Ascend AI Processors

The Ascend AI Processor can work in EP or RC mode. Note the following differences in app development for the two working modes.

Environment Setup

Table 1 Environment setup

Working Mode

See Also

EP

Before setting up the development environment and operating environment, refer to:

CANN Software Installation Guide

RC
  • Atlas 200 AI accelerator module (Model 3000)

    Before setting up the development environment, refer to: CANN Software Installation Guide

    Set up the operating environment by referring to Atlas 200 AI Accelerator Module Software Installation and Maintenance Guide (RC).

App Building

Note the following differences between the two working modes regarding app building in terms of the environment variable configuration and build command.

  • Environment variable configuration
    Table 2 Environment variable configuration

    Working Mode

    Environment Variable

    EP
    • If the development environment and operating environment have the same CPU architecture (x86, for example):
      export DDK_PATH=$HOME/Ascend/ascend-toolkit/latest/x86_64-linux
export NPU_HOST_LIB=$HOME/Ascend/ascend-toolkit/latest/x86_64-linux/compiler/lib64/stub
    • If the development environment uses the x86 architecture while the operating environment uses the Arm architecture:
      export DDK_PATH=$HOME/Ascend/ascend-toolkit/latest/arm64-linux
export NPU_HOST_LIB=$HOME/Ascend/ascend-toolkit/latest/arm64-linux/runtime/lib64/stub

    RC

    In RC mode, the development environment runs Ubuntu (x86) while the operating environment runs Ubuntu (Arm). Configure the following environment variables:

    export DDK_PATH=$HOME/Ascend/ascend-toolkit/latest/arm64-linux
export NPU_HOST_LIB=$HOME/Ascend/ascend-toolkit/latest/arm64-linux/runtime/lib64/stub

    $HOME/Ascend/ascend-toolkit/latest in the environment variable configuration in the table is for reference only.

    • In EP mode, replace it with the actual standard-form compiler or Runtime installation path.
    • In RC mode, replace it with the actual MiniRC-form Runtime installation path.
  • Build command
    Table 3 Build command

    Working Mode

    Environment Variable

    EP
    • If the CPU architecture of the development environment matches that of the operating environment:
      cmake ../../../src -DCMAKE_CXX_COMPILER=g++ -DCMAKE_SKIP_RPATH=TRUE
    • If the CPU architecture of the development environment differs from that of the operating environment:
      cmake ../../../src -DCMAKE_CXX_COMPILER=aarch64-linux-gnu-g++ -DCMAKE_SKIP_RPATH=TRUE

    RC

    In RC mode, the development environment runs Ubuntu (x86) while the operating environment runs Ubuntu (Arm). The build command is:

    cmake ../../../src -DCMAKE_CXX_COMPILER=aarch64-linux-gnu-g++ -DCMAKE_SKIP_RPATH=TRUE
Parent topic: Appendixes