ZBrushCentral

Zbrush low subdivision

hi, i am new with that program and when i try to load character “julie” for example, i see her low poly insted of high subdivision (?)
also, when i use brushes i see low result on the sculpter as well… for some reason?
when i see youtube guides the brusehs and everything seem to be really smooth…
it might be my graphic card? i have 2 (and both great)
how do i know which graphic card Zbrush decide to use?

p.s sorry for my english