Apologies in delayed response.
Once the workload is migrated to Azure, for getting throughput in Gigs, this can be achieved by Express Route. If the data has to be moving from on-prem to Azure depending on your use-cases.
Please check the NW through puts documentation for more details here.
If the SQL is migrated to azure VM as IaaS, then please ensure you select recommended VM Type and disk type for IOPS and Throughput.
If you are planning to use Azure SQL Managed Instances read more info here.
Please check these links for SQL Server best practices and performance guidance:
Also, please check the SQL Migration Features comparison here.
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