[severgun]

Hello, guys.

Is there any enthusiasts which benchmark and tune linux distros for best performance in star-ccm+? Can you give me an advice?

I have HPC cluster with netboot image based on Debian 7(kernel 3.2.63) without noticeable tuning. I tried to do some starccm+ benchmarks at one node with 4 Opteron CPUs (1-64cores)

/opt/StarCCM/STAR-CCM+12.02.010/star/bin/starccm+ -locale en:US -power -pio -benchmark:"-preits 1 -nits 10 -tag opteron_63 -nps 1,2,4,8,16,24,32,40,48,63,64" -on localhost -np 64 -cpubind v /home/user/test.sim

Debian 7(3.2.63) vs Debian 9(4.9.30) vs CenOS 7(3.10.0) and both new distros are worse
(upto -10%) than old one.
So I have a couple of questions:
1) Which distro is the best. May be someone done this research?
2) New distos(kernels) are so bad or I'm doing something wrong?
3) Is it possible to tune performance for ccm+? If so, can you tell me how to do it?