[CentOS] Performance issues/difference of two servers running same task (one is quicker)

Thu Jul 4 17:46:19 UTC 2019
Gordon Messmer <gordon.messmer at gmail.com>

On 7/3/19 11:43 PM, Jobst Schmalenbach wrote:
>   - How can it be that the DELL takes so much longer alltough on the far better hardware?

It looks like the DIY system has a CPU that's nearly twice as fast as 
the Dell's.  The additional CPU in the Dell will run more tasks 
concurrently, but it won't make a single process faster.

You might also think that the SSD RAID would make the Dell faster, but 
that will only be true if the process that you're testing performs a 
significant amount of IO.  If your DB operations are happening mostly in 
memory (that is, if the data is cached), then the faster CPU will be the 
primary determining factor.

The other thing that you left out of your description is the amount of 
data on each server.  If your live server has a lot of data in its DB 
and the dev system has a small dataset suitable for testing, then 
generally you'd expect that the dev system's data is more likely to live 
in cache and avoid disk IO, and processing the smaller set will also 
take less CPU time.