Performance in lich king with dranor models

Hello, i coudnt find any usefull info about something like this, but story is short ! Performance for me is kinda not ao good , low fps in sw and dalaran! No where else.
I play on laptop i7 6700hq 960m 4gb. Playing 1080p with like medium settings , in dalaran sometimes drops down to 20fps and same in stormwind ! What is wrong here or it is only for me.? I play legion to and that is on high settings , and it is 45+ fps stady like a rock, every where. What could be problem?

There is no problem, that is just how it is. Realm is oversaturated with people. In hubs FPS falls down.
I use legion models and in Dalaran its same stuff - 25fps. Even without models fps drop is huge.

If you get CTD's in hubs, try large adress aware if you don't already.