Power BI Premium performance issue

Hi unisong114 

There are many things to consider as to why it appears to be slower.

Have a look at the dataset size using DAX studio, make it as small as possible by removing unwanted columns. Also make sure that you are using a Star Schema. And finally make sure that your measures are as fast as possible.

After that I would suggest looking at the different Premium options such as Premium P Nodes, Premium Per User and then Power BI Pro.

Addition to what GilbertQ  suggested, you can track usage of your premium capacity using APP Monitor Power BI Premium capacities with the Premium Capacity Metrics app. - Power BI | Microsoft Docs that will help analying what is consuming most of resources of premium capacity.

If this post helps, then please consider Accept it as the solution, Appreciate your Kudos!

Hi,  unisong114 

You can monitor report performance in Power BI Desktop using the Performance Analyzer, and monitor performance of content deployed into your organization's Power BI Premium capacity with the help of the Power BI Premium Metrics app. You can also use SQL Server Profiler to identify queries that are slow.

For more information, please check out the following resources:

• Troubleshoot report performance in Power BI 
• Query Diagnostics
• Performance Analyzer
• Troubleshoot report performance in Power BI
• Power BI Premium Metrics app   

Best Regards,
Community Support Team _ Eason