All Pro Tools versions including and after 12.5 have shown an extremely high processor usage for a Windows computer using Lynx AES 16e interface cards or Lynx Thunderbolt interfaces. This behavior exists prior to opening a project, and at all buffer settings. Windows resource monitor indicates 100% CPU usage of the first thread, and normal 0 - 5% usage of all other threads. The Lynx cards works with other DAW softwares under the current configuration. The high CPU usage does not occur in PT Version 12.4. The problem still persisted after performing a clean install of Windows and Pro Tools, with no 3rd party plugin installed.