[Hasknewbie]

"this review shows that the 16-core 2950X compiles Chromium faster than the 32-core 2990WX, presumably this means something other than the thread count becomes a bottleneck after 16 threads"

The article mentions that, due to the die packaging, only 16 of the cores have direct access to RAM. So for the 32-core version, half the cores are memory-starved and have to go through the 'connected' cores (also impacting these), while the 16-core version doesn't have that problem and can be at 100% for all process loads.

[znpy]

Might memory access model (UMA vs NUMA) play a role here? AFAIK the TR2950wx has configurable model (can be configured to work in either uma or numa mode) whereas the 2950x only has one mode (can't recall which one at the moment)

[snuxoll]

It's the opposite, the 2950X can be configured in (fake-)UMA ("distributed" mode in AMD's terms) or NUMA mode but the WX chips are NUMA only.

[deng]

I would think that compilation is faster on the 32Core, but linking is much slower.

[compilerdev]

See my other answer in this threaad, the main reason for the strange result is doing an LTCG build, not really the CPU, which scales quite nicely in the Linux tests from Phoronix.