The SQL CPU by Hour of Day report lets you see what the average CPU load was per hour for the last week.
The SQL CPU Load by Hour of Day is an instance level report that was added just prior to the Version 2.0 release. This report was not in any of the earlier beta releases.
What is really nice with this report is you can see where your hot spots are for the last week on CPU load. It helps identify times that you have high CPU load and low CPU load, and from there you can look at things like jobs, ETL work, or other scheduled items that could be shifted around to better balance the load on the database. It may also show you if your SQL Server is bound by CPU at some part of the week. This could be an indicator that you need more CPU, either by adding more processors to a virtual machine, or by upgrading your physical hardware.
If this report shows minimal load, it could be a sign that you could take away CPU from the VM, or that this server may be a candidate for consolidation. For instance if you have 5 SQL Servers that are all underutilized you may be wasting valuable SQL Server licenses. Consolidating those multiple servers onto a single sever may reduce your licensing costs.
To use the CPU by Hour of Day report, you need to have Historic Monitoring enabled for your SQL Server instance.