Update README.md

[ROCm/rccl-tests commit: 17d0a42d5a]

projects/rccl-tests/README.md

@@ -49,7 +49,7 @@ All tests support the same set of arguments :
   * `-b,--minbytes <min size in bytes>` minimum size to start with. Default : 32M.
   * `-e,--maxbytes <max size in bytes>` maximum size to end at. Default : 32M.
   * Increments can be either fixed or a multiplication factor. Only one of those should be used
-    * `-i,--stepbytes <increment size>` fixed increment between sizes. Default : (max-min)/10.
+    * `-i,--stepbytes <increment size>` fixed increment between sizes. Default : 1M.
     * `-f,--stepfactor <increment factor>` multiplication factor between sizes. Default : disabled.
 * NCCL operations arguments
   * `-o,--op <sum/prod/min/max/avg/all>` Specify which reduction operation to perform. Only relevant for reduction operations like Allreduce, Reduce or ReduceScatter. Default : Sum.