diff contrib/pg_test_fsync/pg_test_fsync.c
index 9fe2301..7f7368a
*** a/contrib/pg_test_fsync/pg_test_fsync.c
--- b/contrib/pg_test_fsync/pg_test_fsync.c
***************
*** 25,31 ****
  
  #define LABEL_FORMAT		"        %-32s"
  #define NA_FORMAT			"%18s"
! #define OPS_FORMAT			"%9.3f ops/sec"
  
  /* These are macros to avoid timing the function call overhead. */
  #ifndef WIN32
--- 25,32 ----
  
  #define LABEL_FORMAT		"        %-32s"
  #define NA_FORMAT			"%18s"
! #define OPS_FORMAT			"%9.3f ops/sec (%6.f microsecs/op)"
! #define USECS_SEC			1000000
  
  /* These are macros to avoid timing the function call overhead. */
  #ifndef WIN32
*************** print_elapse(struct timeval start_t, str
*** 568,575 ****
  	double		total_time = (stop_t.tv_sec - start_t.tv_sec) +
  	(stop_t.tv_usec - start_t.tv_usec) * 0.000001;
  	double		per_second = ops / total_time;
  
! 	printf(OPS_FORMAT "\n", per_second);
  }
  
  #ifndef WIN32
--- 569,577 ----
  	double		total_time = (stop_t.tv_sec - start_t.tv_sec) +
  	(stop_t.tv_usec - start_t.tv_usec) * 0.000001;
  	double		per_second = ops / total_time;
+ 	double		avg_op_time_us = (total_time / ops) * USECS_SEC;
  
! 	printf(OPS_FORMAT "\n", per_second, avg_op_time_us);
  }
  
  #ifndef WIN32
diff doc/src/sgml/pgtestfsync.sgml
index 95ba3b8..00ef209
*** a/doc/src/sgml/pgtestfsync.sgml
--- b/doc/src/sgml/pgtestfsync.sgml
***************
*** 30,40 ****
    <application>pg_test_fsync</> is intended to give you a reasonable
    idea of what the fastest <xref linkend="guc-wal-sync-method"> is on your
    specific system,
!   as well as supplying diagnostic information in the event of an
!   identified I/O problem.  However, differences shown by <application>pg_test_fsync</application>
!   might not make any difference in real database throughput, especially
!   since many database servers are not speed-limited by their transaction
!   logs.
   </para>
   </refsect1>
  
--- 30,43 ----
    <application>pg_test_fsync</> is intended to give you a reasonable
    idea of what the fastest <xref linkend="guc-wal-sync-method"> is on your
    specific system,
!   as well as supplying diagnostic information in the event of an identified I/O
!   problem.  However, differences shown by
!   <application>pg_test_fsync</application> might not make any significant
!   difference in real database throughput, especially since many database servers
!   are not speed-limited by their transaction logs.
!   <application>pg_test_fsync</application> reports average file sync operation
!   time in microseconds for each wal_sync_method, which can be used to inform
!   efforts to optimize the value of <varname>commit_delay</varname>.
   </para>
   </refsect1>