The latest 1.6.382 alpha previews some major updates to the engine, the application and compilation targets.
Along with a new (additional!) Denoise 2 module, much work has gone into further optimisations and making the engine more CPU data cache friendly. Furthermore, two new executables have been added to take advantage of newer instruction sets found in modern systems (from Intel Haswell, or AMD Excavator and Ryzen CPUs onward). These executables have the postfix 'AVX2'.
Regardless of the executable version you are running, you should notice considerable speedups across the board, especially compared to 1.5 and lower.
Given that this alpha release has a lot of work done under the hood, I am keen to hear from you how the engine is behaving and any feedback you might have. Thank you in advance!