[asterisk-users] Asterisk multi-cpu

[David Backeberg]

On Thu, Mar 26, 2009 at 3:06 PM, Mike <list at virtutel.ca> wrote:
> Hi,
>
> I know somebody is going to give me the link to the wiki hardware pages, but
> I can't find the answer there. I'd like to know if, for an Asterisk only
> system (nothing else of note running on it), I get a real gain from having 2
> CPUs.
>
> Does the amount of traffic/SIP registrations/codec translation possible
> doubles with 2 CPUs? (each quad core E5420 to be precise)? Does it increase
> by 50%?  It is only a marginal increase, or none at all?

You don't say anything about your possible kind of usage, so it's
difficult to provide any specific answer to your question. In general,
a few things are true:
* asterisk is multi-threaded
* linux kernel has nice job schedulers and i/o schedulers
* if you have more ram, more things will get cached in ram
* if you have more cpus / cores you can do more things at once as long
as they aren't all idle waiting for some resource constraint

You need to run a LOT of traffic through a server if it's just
straight call handling, with a minimum of disk-bound i/o or
transcoding, before you're going to max out modern hardware. So just
buy the best server you want to buy, but save some money for a good
warranty, or buy two servers if that's cheaper than what it would cost
to be down.

If you want more in-depth discussions on this you probably would
prefer the asterisk-ha-clustering list:
http://lists.digium.com/mailman/listinfo/asterisk-ha-clustering