How would you reduce the time it takes to compile reports in Google Analytics?
Remove any filters you have added to the view
Choose “Faster response” in the sampling pulldown menu
Choose “Greater precision” in the sampling pulldown menu
Remove any Secondary Dimensions you have added to the report
At the top of the report, below the date range selector, select Faster response, less precision or Slower response, greater precision. Your data automatically refreshes using the new setting. Your preference is saved across all of your reports, but resets after you close Analytics.
Read more here: https://support.google.com/analytics/answer/1733979