mirror of https://gitlab.com/QEF/q-e.git
76 lines
2.5 KiB
Markdown
76 lines
2.5 KiB
Markdown
Quantum ESPRESSO GPU
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====================
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[](https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html)
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This repository also contains the GPU-accelerated version of Quantum ESPRESSO.
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Installation
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============
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This version requires the nvfortran (previously PGI) compiler from the
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freely available NVidia HPC SDK. You are advised to use the most recent
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version of NVidia software you can find. While any version later than 17.4
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should work, many glitches are known to exist in older versions.
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The `configure` script checks for the presence of the nvfortran compiler and
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of a few cuda libraries. For this reason the path pointing to the cuda toolkit
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must be present in `LD_LIBRARY_PATH`.
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A template for the configure command is:
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```
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./configure --with-cuda=XX --with-cuda-runtime=YY --with-cuda-cc=ZZ --enable-openmp [--enable-openacc] [ --with-scalapack=no ]
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```
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where `XX` is the location of the CUDA Toolkit (in HPC environments is
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generally `$CUDA_HOME`), `YY` is the version of the cuda toolkit and `ZZ`
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is the compute capability of the card. You can get those numbers from
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command `nvaccelinfo`, if you have a properly configured HPC SDK:
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```
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$ nvaccelinfo | grep -e 'Target' -e 'Driver'
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CUDA Driver Version: 11000
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Default Target: cc70
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...
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```
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The version is returned as (1000 major + 10 minor). For example, CUDA 9.2
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would be represented by 9020. For the above case, configure QE with:
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```
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./configure --with-cuda=$CUDA_HOME --with-cuda-cc=70 --with-cuda-runtime=11.0
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```
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Alternatively, you may use the (deprecated) tool `get_device_props.py` in
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directory `dev-tools/`.
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It is generally a good idea to disable Scalapack when running small test
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cases since the serial GPU eigensolver outperforms the parallel CPU
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eigensolver in many circumstances.
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From time to time PGI links to the wrong CUDA libraries and fails reporting a
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problem in `cusolver` missing `GOmp` (GNU Openmp). This problem can be solved
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by removing the cuda toolkit from the `LD_LIBRARY_PATH` before compiling.
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Serial compilation is also supported.
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Execution
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=========
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By default, GPU support is active. The following message will appear at
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the beginning of the output
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```
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GPU acceleration is ACTIVE.
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```
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GPU acceleration can be switched off by setting the following environment
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variable:
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```
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$ export USEGPU=no
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```
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Testing
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=======
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The current GPU version passes all tests with both parallel and serial
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compilation.
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