Applies To: Windows 8, Windows 8.1

Enables and configures symbol decoding support.

xperf -i <trace file>… [-o output] -symbols [cacheonly] [verbose] [dbghelplog]


  • cacheonly
    Use SymCache, but not DbgHelp. This option speeds symbol decoding for traces with many binary images that lack symbol files after all interesting symbol files have been transcoded.
  • verbose
    Verbose mode. Prints symbol paths and version information. For more information, see Loading Symbols.
  • dbghelplog
    Enable DbgHelp debug log about stderr.

    Symbol decoding support uses the environment variables in the following table for further configuration of DbgHelp and SymCache.


Specifies the DbgHelp path to search to locate symbols files (with the file name extension of .pdb) corresponding to binary images files used in the trace. See the note below regarding this variable.


Specifies the path to the local SymCache directory. By default, \SymCache is used.


For symbol decoding, the trace must be a kernel trace (or a user trace processed in conjunction with a kernel trace) that has the PROC_THREAD+LOADER kernel flags enabled and that has been stopped and merged with -d or with -merge on the computer on which it was taken. Xperf performs a special image identification process during its custom trace merge that enables symbol decoding.


If this action is not specified on the command line, symbol decoding is disabled.

See Also


Missing Symbols


Loading Symbols

Other Resources

Xperf Options