This is the test I remember:
https://www.pugetsystems.com/labs/articles/Adobe-Premiere-Pro-CC-Multi-Core-Performance-698/
Note that they used dual 10 core processors and it seems that they tested physical cores - not hyper threading virtual cores. 4k preview is the most challenging and important task for me. According to the benchmarks - up to 10 cores scales rather linearly, could be related to it being all on one of the CPUs? Above 10 cores it continues to go up a bit. But clearly it may be that 6 cores at 4+ghz will be pretty close to 16 cores at 2.6 ghz.
For rendering - I'm rarely time limited, but the ability to leave some cores untouched means I can continue to do other work seamlessly.
https://www.pugetsystems.com/labs/articles/Adobe-Premiere-Pro-CC-Multi-Core-Performance-698/
Note that they used dual 10 core processors and it seems that they tested physical cores - not hyper threading virtual cores. 4k preview is the most challenging and important task for me. According to the benchmarks - up to 10 cores scales rather linearly, could be related to it being all on one of the CPUs? Above 10 cores it continues to go up a bit. But clearly it may be that 6 cores at 4+ghz will be pretty close to 16 cores at 2.6 ghz.
For rendering - I'm rarely time limited, but the ability to leave some cores untouched means I can continue to do other work seamlessly.