OWTAS sets a number of additional critical and delayed worker threads, plus service work items. The changes are autocalculated according to a combination of RAM and OS bit-width (32 vs. 64). Performance will increase, more so with more RAM. Available as VBS and as PowerShell 3 and up. Future development will be in PowerShell, as part of the windows-tools project.
The tool is designed for Windows 10 down through XP. As of 2017-10-10, it is self-elevating if run non-administratively.