Ok, if you want something off the shelf, then there are things like this: https://www.meinbergglobal.com/english/products/pci-express-clocks.htm https://www.me

Ok, if you want something off the shelf, then there are things like this: https://www.meinbergglobal.com/english/products/pci-express-clocks.htm https://www.meinbergglobal.com/english/products/pci-express-... But I don't know what functionality they actually provide available over the pci-express port, if one is unlucky, it's only the serial port to the GPS receiver ;-).