[App_rpt] CPU Load

John Yaldwyn jy at 4hf.net
Mon Oct 27 20:13:02 UTC 2008


Hi All,

Recently there was a brief discussion as to CPU performance.

Over the weekend I had the opportunity to look at the CPU loading of two
systems I run.

Both systems are built from the ACID distribution with the following
changes:

Node update script disabled
Sendmail disabled
Digium G.729 codec loaded
Admin and Webmin interfaces disabled
Required modules only loaded

Neither system uses Iptables and both are located behind Linksys BEFSR41
routers with fixed IP addresses.
'netstat -ta' shows only the SIP, IAX2, and SSH ports open.
Both systems uses IBM Serve RAID hardware RAID level 1 using 18GB 15K
RPM drives.

System 1 consists of an IBM x345 single CPU PIII-S 1.133MHz Server with
512KB cache and 2GB RAM.
'less /proc/cpuinfo' shows BOGOMIPS of 2257.

'top' shows and idle CPU load of 10% for asterisk and negligible load
for any other process.
'free' reports about 419KB used.
'swapon -s' reports swap space usage of 0.

With on USB connected repeater active (ongoing voice conversation) and
an independent voice call set up using a Linksys SIP telephone set using
A law codec connected to a service provider using IAX2 and G.729 top
showed a peak load of 22%.


System 2 consists of an IBM x345 single XEON 2GHz HT capable Server with
512KB cache and 2 GB RAM.
'less /proc/cpuinfo' shows BOGOMIPS of 3990.

'top' shows and idle CPU load of 6% for asterisk and negligible load for
any other process.
'free' reports about 500KB used.
'swapon -s' reports swap space usage of 0.

With on USB connected repeater active (ongoing voice conversation) and
an independent voice call set up using a Linksys SIP telephone set using
A law codec connected to a service provider using IAX2 and G.729 top
showed a peak load of 17%.


Looking at the numbers the higher performance XEON system seems to have
made only a marginal improvement at what is admittedly a light load.
But what is more interesting it appears that relatively modest PIII
boxes are fully capable of managing the single repeater type
applications without resporting to something like Limey.

Perhaps PIII 500MHz or more, 768MB RAM, and 2GB or more disk as a
working minimum spec. Note that the Anaconda installer used for CENTOS
in ACID seems to have problems loading with just 512MB of RAM.  I would
be interesetd to hear from anyone running such a configuration.

Using the simple shell comands shown in single quotes above provides a
quick system overview for basic performance evaluation.

Cheers, John ZL4JY






 




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