aCG: GPU-Accelerated Iterative Linear Solvers

aCG is a suite of GPU-accelerated iterative linear solvers based on the conjugate gradient (CG) method. It supports NVIDIA and AMD GPUs, as well as multi-GPU systems utilizing GPU-aware MPI, NCCL, RCCL, or NVSHMEM.

Implementation Details

NVIDIA GPUs

• Core: CUDA implementations of CG and pipelined CG.
• Communication:
  • Host-initiated: GPU-aware MPI, NCCL, or NVSHMEM.
  • Device-initiated: NVSHMEM (performed directly by the GPU).

AMD GPUs

• Core: HIP implementations of CG and pipelined CG.
• Communication:
  • Host-initiated: GPU-aware MPI or RCCL.

Installation and Usage

Please see the file INSTALL for instructions on how to build and install the software.

License

aCG is free software, available under a permissive software license. See the file LICENSE for copying conditions.

Reference

If you use aCG in your research, please cite the following paper:

James D. Trotter, Sinan Ekmekçibaşı, Doğan Sağbili, Johannes Langguth, Xing Cai, and Didem Unat. 2025. CPU- and GPU-initiated Communication Strategies for Conjugate Gradient Methods on Large GPU Clusters. In Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis (SC '25). Association for Computing Machinery, New York, NY, USA, 298–315. https://doi.org/10.1145/3712285.3759774

BibTeX

@inproceedings{Trotter2025,
  author    = {Trotter, James D. and Ekmek\c{c}iba\c{s}\i, Sinan and Sa\u{g}bili, Do\u{g}an and Langguth, Johannes and Cai, Xing and Unat, Didem},
  title     = {CPU- and GPU-initiated Communication Strategies for Conjugate Gradient Methods on Large GPU Clusters},
  booktitle = {Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis (SC '25)},
  year      = {2025},
  publisher = {Association for Computing Machinery},
  address   = {New York, NY, USA},
  pages     = {298--315},
  doi       = {10.1145/3712285.3759774}
}