
Pouya Mohammadi engineered performance-critical features and optimizations across ROCm/rccl and ROCm/rocm-systems, focusing on distributed GPU workloads and collective operations. He delivered tuning enhancements for AllReduce, AllGather, and ReduceScatter, introducing configuration-driven resource allocation and protocol-specific improvements for MI300 and MI350 architectures. Using C++, CUDA, and CMake, Pouya implemented kernel-level profiling, algorithm tuning, and low-level channel management to boost throughput and stability in multi-node environments. His work emphasized reproducibility and maintainability, with clear commit traceability and integration alignment. The depth of his contributions reflects strong expertise in high-performance computing, system programming, and performance optimization for large-scale GPU systems.
January 2026 — Feature delivered for ROCm/rocm-systems: MI350 multi-node communication channel optimization, reducing p2pnChannels from 64 to 32 for send/recv collectives in 2- and 4-node MI350 configurations. Commit: c19441b2b99e2c1033d88198ec31b1efe8e81283. Major bugs fixed: none reported. Impact: improved throughput and resource utilization for multi-node workloads, enabling more efficient 2-4 node deployments. Technologies/skills: low-level IPC/channel tuning, performance optimization in ROCm stack, and traceable changes via commit-based development.
January 2026 — Feature delivered for ROCm/rocm-systems: MI350 multi-node communication channel optimization, reducing p2pnChannels from 64 to 32 for send/recv collectives in 2- and 4-node MI350 configurations. Commit: c19441b2b99e2c1033d88198ec31b1efe8e81283. Major bugs fixed: none reported. Impact: improved throughput and resource utilization for multi-node workloads, enabling more efficient 2-4 node deployments. Technologies/skills: low-level IPC/channel tuning, performance optimization in ROCm stack, and traceable changes via commit-based development.
Month: 2025-12. Delivered a GPU Resource Tuning Configuration for Collective Operations in ROCm/rocm-systems, introducing a tuning config file to optimize GPU resource allocation for allreduce, allgather, and reducescatter across varying node/rank configurations, particularly with under-subscribed GPUs per node. Key commits f0e7e8745f7f783c45d0501e1258fe3914a3d519 and bed6070e1285446f410ca54cf7f7ce820d7d200f implement the tuning file and reference RCCL integration. No major bugs fixed this month; effort focused on feature delivery, documentation, and alignment with RCCL for reproducible builds. Business impact: improved distributed performance, reduced manual tuning, and better deployment consistency across topologies. Technologies demonstrated: config-driven optimization, distributed collectives tuning, RCCL integration awareness, and maintainable versioned changes.
Month: 2025-12. Delivered a GPU Resource Tuning Configuration for Collective Operations in ROCm/rocm-systems, introducing a tuning config file to optimize GPU resource allocation for allreduce, allgather, and reducescatter across varying node/rank configurations, particularly with under-subscribed GPUs per node. Key commits f0e7e8745f7f783c45d0501e1258fe3914a3d519 and bed6070e1285446f410ca54cf7f7ce820d7d200f implement the tuning file and reference RCCL integration. No major bugs fixed this month; effort focused on feature delivery, documentation, and alignment with RCCL for reproducible builds. Business impact: improved distributed performance, reduced manual tuning, and better deployment consistency across topologies. Technologies demonstrated: config-driven optimization, distributed collectives tuning, RCCL integration awareness, and maintainable versioned changes.
November 2025 monthly summary for ROCm/rocm-systems highlighting delivery of BFloat16 intrinsic support and ROCm 6.0.0 compatibility, with kernel-level improvements and clear commits traceability.
November 2025 monthly summary for ROCm/rocm-systems highlighting delivery of BFloat16 intrinsic support and ROCm 6.0.0 compatibility, with kernel-level improvements and clear commits traceability.
2025-06 ROCm/rccl monthly summary focusing on performance optimization for large-scale collectives on MI300X. Delivered channel tuning enhancements for AllGather and ReduceScatter using LL128 protocol, reapplying a prior optimization PR to introduce thread work thresholds in tuning models and precompute register indices for LL128. Updated tuning parameters and changelog to reflect these changes. These efforts target higher throughput, reduced latency, and improved stability for workloads relying on LL128 on MI300X.
2025-06 ROCm/rccl monthly summary focusing on performance optimization for large-scale collectives on MI300X. Delivered channel tuning enhancements for AllGather and ReduceScatter using LL128 protocol, reapplying a prior optimization PR to introduce thread work thresholds in tuning models and precompute register indices for LL128. Updated tuning parameters and changelog to reflect these changes. These efforts target higher throughput, reduced latency, and improved stability for workloads relying on LL128 on MI300X.
In May 2025, stabilization efforts focused on ROCm/rccl AG/RS channel tuning. The team reverted changes that added a thread work threshold to tuning models and precomputed the register index in LL128, restoring the prior, validated behavior and preventing regressions in tuning paths.
In May 2025, stabilization efforts focused on ROCm/rccl AG/RS channel tuning. The team reverted changes that added a thread work threshold to tuning models and precomputed the register index in LL128, restoring the prior, validated behavior and preventing regressions in tuning paths.
April 2025 performance and optimization focus for ROCm/rccl. Delivered two MI300-specific enhancements in MSCCL to boost both single-node and multi-node AllReduce performance on MI300-based systems, driving improved throughput for distributed deep learning workloads and better scaling across nodes.
April 2025 performance and optimization focus for ROCm/rccl. Delivered two MI300-specific enhancements in MSCCL to boost both single-node and multi-node AllReduce performance on MI300-based systems, driving improved throughput for distributed deep learning workloads and better scaling across nodes.
February 2025 monthly summary for ROCm/rccl. Focused delivery and stabilization across key features and fixes, aligned to business value and hardware coverage. Month: 2025-02.
February 2025 monthly summary for ROCm/rccl. Focused delivery and stabilization across key features and fixes, aligned to business value and hardware coverage. Month: 2025-02.
January 2025 performance instrumentation and profiling work focused on the microsoft/mscclpp/nccl integration. Key feature delivered: NPKIT-based profiling support for kernel allreduce7 in mscclpp-nccl, enabling detailed event collection and performance data to drive optimizations for allreduce workloads. This included code and build integration across CMakeLists.txt, allreduce.hpp, and nccl.cu to enable NPKIT instrumentation.
January 2025 performance instrumentation and profiling work focused on the microsoft/mscclpp/nccl integration. Key feature delivered: NPKIT-based profiling support for kernel allreduce7 in mscclpp-nccl, enabling detailed event collection and performance data to drive optimizations for allreduce workloads. This included code and build integration across CMakeLists.txt, allreduce.hpp, and nccl.cu to enable NPKIT instrumentation.

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