@Hubert Dudek Thanks for your suggestions.
After creating storage account in same region as databricks I can see that performance is as expected.
Now it is clear that issue is with /mnt/ location is being in different region than databricks.
I would like to understand why it takes 13x more time to write data to different region storage compared to same region storage account?
What is API / protocol does databricks uses in backend to write data to same region and different region ?
Why I concerned is because we are developing service for customers.
Customer can choose storage account region and data bricks account region while deploying this service in their subscription.
If both are different, then customer will face performance issues as I reported earlier.
@Kaniz Fatma Kindly help here in understanding it takes 13x more time to write data to different region storage compared to same region storage account?