This section describes the communication operators supported by the Atlas training product.

Single-operator zero-copy: To reduce the memory copy overhead, HCCL can directly operate the memory transferred by the service to improve communication performance.
Communication operator retry: When the communication is intermittently interrupted due to a network fault, HCCL attempts to retry the communication operator to improve communication stability.
Deterministic computing: The same output is generated if a reduction communication operator is executed for multiple times with the same hardware and input.

The Atlas training product supports communication operators only in host expansion mode.
In the table, "√" indicates supported, "☓" indicates unsupported, and "N/A" indicates not involved. The Atlas training product does not support single-operator zero-copy or operator retry.
Operators and network modes not listed are not supported.

Operator	Network Mode	Single-Operator Zero-Copy	Deterministic Computing	Retry	Intra-Rank Communication	Inter-Rank Communication
Broadcast	Single-operator	☓	N/A	☓	√	√
Broadcast	Graph (Ascend IR)	☓	N/A	☓	√	√
AllGather	Single-operator	☓	N/A	☓	√	√
AllGather	Graph (Ascend IR)	☓	N/A	☓	√	√
Reduce	Single-operator	☓	√	☓	√	√
Reduce	Graph (Ascend IR)	☓	√	☓	√	√
AllReduce	Single-operator	☓	√	☓	√	√
AllReduce	Graph (Ascend IR)	☓	√	☓	√	√
Scatter	Single-operator	☓	N/A	☓	√	√
Scatter	Graph (Ascend IR)	☓	N/A	☓	√	√
ReduceScatter	Single-operator	☓	√	☓	√	√
ReduceScatter	Graph (Ascend IR)	☓	√	☓	√	√
AlltoAll	Single-operator	☓	N/A	☓	√	√
AlltoAll	Graph (Ascend IR)	☓	N/A	☓	√	√
AlltoAllV	Single-operator	☓	N/A	☓	√	√
AlltoAllV	Graph (Ascend IR)	☓	N/A	☓	√	√
Send	Single-operator	☓	N/A	☓	√	√
Send	Graph (Ascend IR)	☓	N/A	☓	√	√
Recv	Single-operator	☓	N/A	☓	√	√
Recv	Graph (Ascend IR)	☓	N/A	☓	√	√
BatchSendRecv	Single-operator	☓	N/A	☓	√	√
BatchSendRecv	Graph (Ascend IR)	☓	N/A	☓	√	√

Atlas Training Products