Upgrade to dual-core (Pentium D) processor - Does it worth it?

Eric Anderson anderson at centtech.com
Fri Jul 14 17:05:07 UTC 2006

On 07/14/06 11:52, Tobias P. Santos wrote:
> Hello!
> We have a server running FreeBSD 5.4 i386 (which we plan to upgrade to 
> 6.1) with a single Pentium 4 2.8GHz processor without SMP kernel.
> This machine basically serves web pages that may or may not use MySQL 
> server (also run in this server).
> Usually, we have low usage and load average is ~ 0.2 which is ok, but 
> sometimes, one single process (e.g., mysqld) begins to use all CPU 
> cycles, loading up the system and leading the other smaller processes 
> (in terms of CPU usage) to have a high response time.
> As this server's motherboard doesn't support an additional processor, we 
> are wondering whether a Pentium D processor (830) might help to minimize 
> this problem.
> In our understanding, one core would be busy with mysqld for example, 
> while the other one would be free to handle other processes like httpd 
> and serve pages that don't even need mysql resources.
> Is this correct? Did someone have similiar (successful or unsuccessful) 
> experiences?

This isn't a clear cut yes/no situation I don't think, but for mysqld, 
there's a lot of tuning you could probably do to make the cpu time drop 
and free up more cycles for other processes.  There's been discussions 
in the past on this list about mysql, but if you have already done all 
the optimizations that you can with mysql (with indexes and such for 
instance), then the extra processor would definitely allow the other 
non-database blocked web pages to be served, as long as you aren't 
actually IO bound somewhere.  I don't know how much memory you have in 
the current machine, but adding more might be a good quick upgrade (that 
is fairly cheap probably).


Eric Anderson        Sr. Systems Administrator        Centaur Technology
Anything that works is better than anything that doesn't.

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