LikwidMarkerAPIPitfalls.md

@@ -157,6 +157,17 @@ LIKWID_MARKER_INIT;
 LIKWID_MARKER_CLOSE;
 ```
 
+If we look at an output with `LIKWID_MARKER_REGISTER`, the runtime variation is gone:
+
+```
++-------------------+----------+----------+----------+----------+----------+----------+
+|    Region Info    |  Core 0  |  Core 1  |  Core 2  |  Core 3  |  Core 4  |  Core 5  |
++-------------------+----------+----------+----------+----------+----------+----------+
+| RDTSC Runtime [s] | 0.998868 | 0.998894 | 0.998902 | 0.998866 | 0.998937 | 0.998862 |
+|     call count    |       20 |       20 |       20 |       20 |       20 |       20 |
++-------------------+----------+----------+----------+----------+----------+----------+
+```
+
 # What about `LIKWID_MARKER_THREADINIT`?
 
 In LIKWID 3 and 4, the application threads needed to be registered in the MarkerAPI using `LIKWID_MARKER_THREADINIT`. This is not required anymore because the MarkerAPI is able to determine new threads by itself (Version 5). The call is still present and can be called but commonly has no effect anymore. There is **one** exception: