The improvements, which can be seen in Microsoft Edge build 81.0.389.0 is due to “new toolchain optimizations” and can be seen in day to day browser use.
In Microsoft’s testing the updated browser us up to 13% faster in the Speedometer 2.0 benchmark when compared to Microsoft Edge 79.
The Speedometer 2.0 benchmark is considered a good proxy for real-world performance across a number of different subsystems
Microsoft would like Edge fans to confirm the improvements by testing the latest Canary version versus the current Edge Dev and Beta versions, which do not have the enhancements yet.
Find those at the Edge Insider download page here.