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MrUnderhill | 7 years ago

For compiling, having many cores is fantastic. Granted, on a workstation, compilation normally just involves a few files (the ones that have changed since the previous build and their dependencies), but when you have to do a full rebuild, it is fantastic to be able to do `make -j16` and watch it chug through 16 files simultaneously. Interestingly, the benchmark in 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 or so.

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Hasknewbie|7 years ago

"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|7 years ago

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)

deng|7 years ago

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

compilerdev|7 years ago

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.

philjohn|7 years ago

this.

One of the projects I compile at work can take an hour running on 4 threads, jack that up to 16 and you take that down to not much over 17-18 minutes. That's a whole heap of developer time you just got back that would have been wasted on compiler swords.

The other one is running VM's/a docker swarm locally for development.

coss|7 years ago

I make games and can't use the incredibuild server at home, so a workstation with even 16 cores would be amazing.