Update README.md

Author: louie-tsai

hardware/priority_core_turbo/README.md

@@ -402,7 +402,8 @@ perfspect --help | head
 </details>
 
 ### Run the benchmark
-
+By using PerfSpect benchmark feature, it generates a diagram of CPU frequency among different number of active CPU cores.  
+The diagram helps us to understand whether PCT cores can reach the right CPU frequency.  
 Run the full flow with [run_host_perfspect_benchmark.sh](run_host_perfspect_benchmark.sh) :
 
 ```bash