The Windows 10 Control Flow Guard security feature has been discovered to contain significant performance issues when launching large executables. Microsoft has since created a fix and it is ready to go for release in a few weeks. The issue was first discovered by Vivaldi when they added Windows 10 machines to their browser unit testing cluster, which prior to that was using only Windows 7. This issue was related to the Windows 10 exploit protection feature called control Flow Guard (CFG) This feature is a feature that protects processes from exploits that target memory corruption vulnerabilities.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-security-feature-slows-launching-of-large-programs/