https://arstechnica.com/gadgets/2018/07/we-tested-throttling-on-the-macbook-pro-now-apple-says-it-has-a-firmware-fix/ > Today, Apple will release macOS High Sierra 10.13.6 Supplemental Update—an update the company says will fix the widely reported performance throttling problem with the new, 2018 MacBook Pro. > Since the device's launch about a week ago, some users reported that sustained, heavy utilization of both the CPU and the GPU caused the 15-inch MacBook Pro's Intel Core i9 processor to drop below its base clock frequency, negatively impacting performance for some demanding workloads.