Intel® oneAPI Collective Communications Library (oneCCL) Developer Guide and Reference
                    
                        ID
                        772609
                    
                
                
                    Date
                    6/30/2025
                
                
                    Public
                
            Fusion of Communication Operations
In some cases, it may be beneficial to postpone execution of communication operations and execute them all together as a single operation in a batch mode. This can reduce operation setup overhead and improve interconnect saturation.
oneCCL provides several knobs to enable and control such optimization:
- The fusion is enabled by CCL_FUSION. 
- The advanced configuration is controlled by: 
     NOTE: 
   
 For now, this functionality is supported for allreduce operations only.