> Our testing with public benchmarks has shown that the changes in the December 2017 updates resulted in no measurable reduction in the performance of macOS and iOS as measured by the GeekBench 4 benchmark, or in common Web browsing benchmarks such as Speedometer, JetStream, and ARES-6.
This is incredibly deceptive, because web workloads are precisely the sort not expected to be impacted by Meltdown most. As I've written elsewhere, it's syscall heavy workloads targeting fast devices, like database software on PCIe SSDs, that will suffer the greatest slowdowns.