[chapplap]

This just means Geekbench isn't good at scaling to multiple cores. It could be the workload or the implementation. If you have the right workload and a good implementation, modern processors do scale reasonably well (all numbers with Threadripper 3970X):

Cinebench R15: 206 single, 7302 multi, 35.4x scaling

POV-Ray: 9:02 single, 0:19 multi, 28.5x scaling

The scaling can be greater than the number of physical cores due to SMT. On the other hand, turbo clocks increases the single-core speed by 10% or more on most CPUs.

[eatmyshorts]

Or they demonstrate that the CPU is throttling cores due to excessive heat. Compare the 24-core 3960x to the 32-core 3970x, and also look at the power consumed when running cores at 100% utilization. It would appear that the 3970x starts throttling the cores once ~21-22 cores are in full utilization, leading the 3970x to be only marginally faster than the 3960x, even though it has 50% more cores. EDIT: 3970x has a GeekBench score of 70655 (single-threaded: 5684) while 3960x has a score of 66676 (single-threaded: 5703; according to https://www.anandtech.com/show/15044/the-amd-ryzen-threadrip...). Meanwhile, power consumption per core starts dropping off significantly at 21 cores for both (https://www.anandtech.com/show/15044/the-amd-ryzen-threadrip...)

[lliamander]

> Meanwhile, power consumption per core starts dropping off significantly at 21 cores for both

Which you would expect with so many cores. Power consumption per core is probably going to be even lower for the 3990X, especially considering it has the same TDP.