We introduce LogGOPSim--a fast simulation framework for parallel algorithms at large-scale. LogGOPSim utilizes a slightly extended version of the well-known LogGPS model in combination with full MPI message matching semantics and detailed simulation of collective operations. In addition, it enables simulation in the traditional LogP, LogGP, and LogGPS models. Its simple and fast single-queue design computes more than 1 million events per second on a single processor and enables large-scale simulations of more than 8 million processes. LogGOPSim also supports the simulation of full MPI applications by reading and simulating MPI profiling traces. We analyze the accuracy and the performance of the simulation and propose a simple extrapolation scheme for parallel applications. Our scheme extrapolates collective operations with high accuracy by rebuilding the communication pattern. Point-to-point operation patterns can be copied in the extrapolation and thus retain the main characteristics...