This parameter specifies the directory where the sync point manager (SPM) logs are written.
If this parameter is null, by default, the logs are written to the sqllib/spmlog directory, which, in a high-volume transaction environment, can cause an I/O bottleneck. Use this parameter to have the SPM log files placed on a faster disk than the current sqllib/spmlog directory. This allows for better concurrency among the SPM agents.