xcode - Pushing from ViewController to TabBarController takes delay -

in project, have viewcontroller login, when pressed login button show viewcontroller b have 4 buttons. when click button1, have showsegue direct tabbarcontroller , has 2 tabs. same button 2,3,4 have showsegue directs navigationcontroller. hierarchy of tabbarcontroller , navigationcontroller:

click button 1 to:

tabbarcontroller ->  tab1 -> navigationcontroller -> viewcontroller1 tab2 -> navigationcontroller -> viewcontroller2 

click button 2,3,4 to:

navigationcontroller -> viewcontroller 

i used storyboard in project running swift 2, xcode 7. when click each buttons, takes 1-2 seconds delays on ipad real device. bad user experience. takes me time search answers sadly didn't found solution, that's why asked here..

thanks in advance.

maybe should think using async method load controllers when press buttons.

try use

dispatch_async(dispatch_get_global_queue(dispatch_queue_priority_default, 0), {  //background thread (get values - run requests)    dispatch_async(dispatch_get_main_queue(), {  //update ui (give values outlets)      }); })