Change Azure Standard to Premium I have one application using SQL Server Standard and would like the change to Premium, but I need to understand about the DTU. The application reaches 100% in DTU every day.

Would talk know if I need to buy Premium with more or equal DTU in Premium or with less DTU for being Premium is enough?

For example, I have the Standard 1600 DTU (S9) and would change to Premium 1000 DTU (P6), would lose the performance this?

Thanks for attention.
Premium tiers all have SSD storage and are intended for IO intensive workloads. DTUs of Standard Tiers do not have the computation power of Premium tiers. Premium tiers have a dedicated hardware on Azure.

If the current workload reaches the DTU limit then throttling may be occurring. Those spikes in DTU may be related to missing indexes (indexes that need to be created) and to queries that need optimization. After creating missing indexes and optimizing some queries you may find DTU consumption is under control and you don't need to scale up the service tier of your database.

Make sure you enable Automatic Tuning to allow Azure create indexes needed on your database. Use Intelligent Insights to understand more if you need to scale up the tier of the database or not.