IPC microbenchmarks do not properly reflect the complex workloads running on post Zen2 microarchitecture. Zen2 upends microarchitecture schematics enough to warrant a different metric.
IPC MB’s, in my experience, tend to benchmark best case scenarios and that is probably the exception rather than the rule for application workloads in modern MA’s. Case in point, microbenchmarks showed significant improvements in IPC for Zen2 in lieu of Skylake yet for the application workload (CPU data bound), Skylake held up neck and neck.
The more appropriate benchmarking metric for post-Zen2 processors is CPI [0].
IPC MB’s, in my experience, tend to benchmark best case scenarios and that is probably the exception rather than the rule for application workloads in modern MA’s. Case in point, microbenchmarks showed significant improvements in IPC for Zen2 in lieu of Skylake yet for the application workload (CPU data bound), Skylake held up neck and neck.
The more appropriate benchmarking metric for post-Zen2 processors is CPI [0].
[0] https://john.e-wilkes.com/papers/2013-EuroSys-CPI2.pdf