TSC timekeeping and cpu states

[Aristedes Maniatis]

On 14/8/17 3:08PM, Kevin Oberman wrote:
> Again, the documentation lags reality. The default was changed for 11.0. It is still conservative. In ALMOST all cases, Cmax will yield the bast results. However, on large systems with many cores, Cmax will trigger very poor results, so the default is C2, just to be safe.
> 
> As far as possible TSC impact, I think older processors had TSC issues when not all cores ran with the same clock speed. That said, I am not remotely expert on such issues, so don't take this too seriously.

Thanks Kevin

What does 'large' and 'many cores' mean here? Is 24 cores large or small? For a server do we ever want the CPU to enter states other than C1?


Ari


-- 
-------------------------->
Aristedes Maniatis
CEO, ish
https://www.ish.com.au
GPG fingerprint CBFB 84B4 738D 4E87 5E5C  5EFA EF6A 7D2E 3E49 102A