performSegueWithIdentifier very slow when segue is modal

Trust me and try this. I have run into this problem a few times.

In Swift 2:

dispatch_async(dispatch_get_main_queue(),{
    self.performSegue(withIdentifier:mysegueIdentifier,sender: self)
})

or for Swift 3:

DispatchQueue.main.async {
    self.performSegue(withIdentifier: mysegueIdentifier,sender: self)
}

As discussed here and here.