Computer systems are complex. Most software applications are distributed and expected to scale. That does not make them any simpler. Further, there is the real world all of that is expected to work in. To analyze performance of such a system isn't less complex. Luckily, there is help. The Open Source universe is full of excellent tools that can help. The talk introduces a few of them. The talk walks down the path of comparing two Linux servers that look pretty much the same from the specs. Introducing test-tools like stress-ng, sysjitter, fio, packetdrill, and friends it is shown how to get a good overview of the systems CPU, memory, disk, and network performance. Since benchmark results are usually time variant a few basic statistical terms are refreshed and used for visualizing those results employing different chart types. The field of performance analysis is wide. There isn't more time in 45 minutes than just to scratch the surface. At the end of the talk the audience will have a few pointers of how to start evaluating their own Linux systems to provide the right performance for their applications.