Yeah, with that CPU you are on the absolute minimum to even potentially be viable. The Entegra system uses ~1-2 threads just to run itself. The physics model for the aircraft also uses ~1 thread. This is even before considering X-Plane and the operating system's needs. With modern CPUs with tons of cores this isn't an issue, but when you are running on a 4 thread total system, its going to be difficult to get running smoothly. We have seen other users find success through closing all other problems and minimizing X-Plane's graphics settings to minimum for ones that relate to CPU, as well as removing additional third party addons/plugins.