A stuttering phenomenon problem, when I use Premiere Pro

hello sir. befor start, please understand my poor english~

my problem is.. when I put video source in PP. then suddenly my work page has stopped really long long time. and it is not getting well.

but if I put picture, it has stopped short time less than 1hour. and getting well.

before ask here. I asked CS team, and I relieved GPU but happend same problem.

Somebody help me please~