I notice in top command, cpu usage is pretty high:
Cpu(s): 0.3% us, 1.0% sy, 0.0% ni, 42.3% id, 3.0% wa, 53.3% hi, 0.0% si
However, I have no idea what "53.3% hi" refers to. I know id = idle, and us=user, sy=system, but what does wa, hi, si eash mean?