When a large number of transactions uses tempdb in SQL Server 2016 and 2017 you may observe increased CPU consumption compared to SQL Server 2014. For example, when you use INSERT INTO temp table consecutively in many separate transactions, then you may observe that the CPU utilization is higher.
This issue is fixed in the following cumulative updates for SQL Server:
- To enable the fix in SQL Server 2016, the Trace Flag 3427 must be enabled.
- To enable the fix in SQL Server 2017, the Common Criteria Compliance (CCC) must be disabled.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.