difference between top and mpstat while stress-ng running

[bellencoATatos]

Hi,
i was running stress-ng on a server with stress-ng --cpu 23.
when i look with top command i have 23 cores with ~100% loading.
but when i passed mpstat comand, i obtain :

node008: 11:19:24 CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle
node008: 11:19:24 all 2.09 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 97.91

i am not sure to understand... any idea ?

i have post the same on stress-ng issues...
ColinIanKing/stress-ng#269
regards
F.