[asterisk-users] Scaling Asterisk: Dual-Core CPUs not yielding gains at high call volumes - Low volume benchmarks - Correction

[Matthew J. Roth]

Luki wrote:
> Perhaps a naive question, but how does 0.137% CPU utilization per call
> equal 1735 MHz per call?
>
> If 1735 MHz / 0.137% = 1735 MHz / 0.00137 => 1266423 MHz at 100%
> utilization ??! Even with 4 CPUs, those would be 316 GHz CPUs.
>
> I think you meant:
> Average CPU utilization per call: 0.137% (~17 MHz)
Luki,

You are absolutely right.  Thank you for pointing out and correcting my 
mistake.

The corrected statistics are below.  Note that the MHz per call 
statistic is calculated with the following formula:

MHzPerCall = (numCPUs * CPUspeed) * (avgCPUperCall * .01)

Thank you,

Matthew Roth
InterMedia Marketing Solutions
Software Engineer and Systems Developer


The Numbers (Corrected)
-----------------------

DC - Incoming SIP to the Playback() application
===============================================
calls   %user   %system   %iowait     %idle
    0    0.00      0.01      0.01     99.98
    1    0.02      0.04      0.00     99.94
    2    0.02      0.06      0.00     99.92
    3    0.03      0.11      0.00     99.86
    4    0.04      0.13      0.00     99.83
    5    0.05      0.16      0.00     99.80
    6    0.05      0.20      0.00     99.75
    7    0.07      0.24      0.00     99.70
    8    0.07      0.25      0.00     99.67
    9    0.08      0.27      0.00     99.65
   10    0.09      0.33      0.00     99.58

Average CPU utilization per call: 0.040% (~9.60 MHz)

SC - Incoming SIP to the Playback() application
===============================================
calls   %user   %system   %iowait     %idle
    0    0.01      0.02      0.00     99.98
    1    0.02      0.10      0.00     99.88
    2    0.03      0.17      0.00     99.80
    3    0.06      0.21      0.00     99.73
    4    0.08      0.28      0.00     99.63
    5    0.10      0.34      0.01     99.55
    6    0.11      0.48      0.00     99.41
    7    0.14      0.49      0.00     99.37
    8    0.16      0.57      0.00     99.28
    9    0.17      0.63      0.01     99.19
   10    0.18      0.75      0.00     99.07

Average CPU utilization per call: 0.091% (~11.52 MHz)

DC - Incoming SIP to the Queue() application - In queue
=======================================================
calls   %user   %system   %iowait     %idle
    0    0.00      0.01      0.00     99.99
    1    0.01      0.03      0.00     99.96
    2    0.01      0.05      0.00     99.94
    3    0.01      0.08      0.00     99.91
    4    0.02      0.10      0.00     99.88
    5    0.03      0.12      0.00     99.84
    6    0.04      0.16      0.00     99.80
    7    0.03      0.17      0.00     99.80
    8    0.04      0.20      0.00     99.76
    9    0.03      0.22      0.00     99.75
   10    0.05      0.27      0.00     99.68

Average CPU utilization per call: 0.031% (~7.44 MHz)

SC - Incoming SIP to the Queue() application - In queue
=======================================================
calls   %user   %system   %iowait     %idle
    0    0.02      0.02      0.00     99.96
    1    0.03      0.07      0.00     99.91
    2    0.03      0.13      0.00     99.83
    3    0.04      0.18      0.00     99.78
    4    0.05      0.23      0.00     99.72
    5    0.06      0.27      0.00     99.67
    6    0.07      0.33      0.00     99.60
    7    0.09      0.38      0.00     99.53
    8    0.09      0.40      0.00     99.51
    9    0.11      0.46      0.01     99.43
   10    0.11      0.48      0.00     99.41

Average CPU utilization per call: 0.055% (~6.97 MHz)

DC - Incoming SIP to the Queue() application - Bridged to an agent
==================================================================
calls   %user   %system   %iowait     %idle
    0    0.00      0.01      0.00     99.99
    1    0.01      0.06      0.00     99.93
    2    0.02      0.14      0.00     99.84
    3    0.03      0.16      0.00     99.81
   
Average CPU utilization per call: 0.060% (~14.40 MHz)
  
SC - Incoming SIP to the Queue() application - Bridged to an agent
==================================================================
calls   %user   %system   %iowait     %idle
    0    0.01      0.02      0.00     99.98
    1    0.02      0.16      0.00     99.82
    2    0.04      0.28      0.00     99.68
    3    0.07      0.36      0.00     99.57

Average CPU utilization per call: 0.137% (~17.35 MHz)