We present an experimental analysis of the scalability of 13 multicore real-time scheduling algorithms on a 48-core AMD platform. The algorithms include G-EDF, P-EDF, C-EDF, and G-NP-EDF. Comparisons are made based on schedulability and tardiness. The algorithms are implemented in a real-time Linux kernel we create called ChronOS. ChronOS extends the Linux kernel's <tt>PREEMPT_RT</tt> patch with a flexible, scalable real-time scheduling framework. Our study shows that it is possible to implement global fixed and dynamic priority real-time scheduling algorithms which will scale to large-scale multicore platforms. Interestingly, and in contrast to the conclusions of prior research, our results reveal that some global scheduling algorithms (e.g., G-NP-EDF) are scalable on 48-core machines. In our implementation, scalability is restricted by lock contention over the global schedule and the cost of interprocessor communication, rather than the global task queue implementation. We show that algorithms implemented with scalability as a first-order goal are able to provide real-time guarantees on our 48-core platform.