Two major trends in high-performance computing, namely, larger numbers of cores and the growing size of on-chip cache memory, are creating significant challenges for evaluating the design space of future processor architectures. Fast and scalable simulations are therefore needed to allow for sufficient exploration of large multi-core systems within a limited simulation time budget. By bringing together accurate high-abstraction analytical models with fast parallel simulation, architects can trade off accuracy with simulation speed to allow for longer application runs, covering a larger portion of the hardware design space. Sniper provides this balance allowing long-running simulations to be modeled much faster than with detailed cycle-accurate simulation, while still providing the detail necessary to observe core-uncore interactions across the entire system. With per-function advanced visualization and coupled power and energy simulations, the Sniper multi-core simulator can provide a fast and accurate way both to understand and optimize software for current and future hardware systems.