Speed of direct query verses import mode

[MEFOX]

I have a pbix with 10 queries. Some queries retrieve about 50k rows of data. If I refresh the version of the pbix built in direct query it completes the refresh in about 30 seconds. When I refresh the import version of this report it takes about 5 minutes. Why is there a such a drastic difference in the refresh time with direct query verses import? 

Thanks, Mark

[lbendlin]

"If I refresh the version of the pbix built in direct query it completes the refresh in about 30 seconds"

 In Direct query it will only refresh the visual that the user has interacted with.  In Import mode the entire dataset is refreshed.