How To Fix RT857 - SMT Mode (On, Off)

SAP Error Message - Details

• Message type: E = Error

• Message class: RT - Monitoring infrastructure MSG and alert texts

• Message number: 857

• Message text: SMT Mode (On, Off)

What causes this issue?

Denotes whether processor simultaneous multi-threading is active. The
simultaneous multi-threading mode allows processors to have thread level
parallelism at the instruction level.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message RT857 - SMT Mode (On, Off) ?

  The SAP error message RT857 related to SMT (Simultaneous Multithreading) mode typically indicates an issue with the configuration of the system's hardware or the settings in the SAP environment regarding the use of SMT. Here’s a breakdown of the cause, potential solutions, and related information:
  Cause:
  
  SMT Configuration: The error may arise if the SMT mode is not properly configured on the server. SMT allows multiple threads to run on a single physical core, which can improve performance but may also lead to issues if not managed correctly.
  Hardware Limitations: The server hardware may not support SMT, or it may be disabled in the BIOS settings.
  SAP Kernel Version: The version of the SAP kernel being used may not be compatible with the current SMT settings.
  Operating System Settings: The operating system may have settings that conflict with the SMT configuration.
  
  Solution:
  
  Check BIOS Settings: Ensure that SMT is enabled in the BIOS settings of the server. This is often found under CPU configuration settings.
  Review SAP Notes: Check for any relevant SAP Notes that may address this specific error. SAP frequently updates its documentation and may have specific recommendations for your version.
  Update SAP Kernel: If you are using an outdated version of the SAP kernel, consider updating it to the latest version that supports your hardware and operating system.
  Operating System Configuration: Review the operating system settings to ensure that they are optimized for SMT. This may include checking CPU affinity settings and other performance-related configurations.
  Consult Documentation: Refer to the SAP documentation for your specific version to understand how SMT is handled and any specific configurations that may be required.
  Contact Support: If the issue persists, consider reaching out to SAP support for assistance. They can provide more tailored guidance based on your specific environment.
  
  Related Information:
  
  Performance Tuning: Understanding how SMT impacts performance can help in making informed decisions about whether to enable or disable it based on your workload.
  System Monitoring: Use monitoring tools to observe the performance of your SAP system with SMT enabled or disabled to determine the best configuration for your needs.
  Compatibility: Always ensure that your hardware, operating system, and SAP version are compatible with each other, especially when making changes to system settings.
  
  By following these steps, you should be able to address the RT857 error related to SMT mode in your SAP environment.