ESXTOP shows one core at near 100% all the time whilst other cores are at 20%, why?

[Dphiance]

Hi as you can see in the screen shot below one of our CPU cores runs at near 100% all the time whilst other cores average ~20%

Does the idle world always run on the first core or is something else happening here?

Thanks

Adam

[Rumple]

the service console is tied to Core 0

run top inside the service console to see what is running so hard inside it to cause high utilization.