General: What is Performance and Throughput Acceleration

         For some  who have played with IxLoad a little  you might have noticed  the following warning   appearing  in IxLoad window log:

          If you  do  a Help search for Performance Acceleration you  will not find  many things about it.

          Unfortunately    we intentionally do not  provide  a lot of information in the Help Guide  in order to  not inform competition about  our capabilities.

     What I can tell you is that the option does  exactly what the title implies,  increase performance by  loading a different TCP stack ( linux  vs ixstack ) depending on your test configuration.

     By default  performance acceleration is enabled but in case card or commands in your test is not supporting it, it gets disabled  at the start of the test.

     You should enable just one  depending on what you want to test and the cards you have.

 If both are enabled TPUT acceleration takes precedence. 

TPUT acceleration  has a little better results that performance acceleration for TPUT objective.

         This increase in performance applies only for  some activities commands and not all the card  support it.

example of cards which support Performance Acceleration:

   Xcellon-Ultra NG/NP/XP, NGY-NP, XT80, 

example of cards that support   Throughput Acceleration:

   NGY-NP

example of commands that  support Performance Acceleration: 

    HTTP GET command, HTTP GET_SSL  command,  DNS query A,AAA,NS record types

example of commands that support Throughput Acceleration:

     HTTP GET command

****If you combine in one NetTraffic activities that support PA and some which do not support, PA is going to be disabled  at test start.

****The list of commands/ports that support performance/tput acceleration provided in this blog is not complete and also more support might be added to other  in the future.

****If you would like to know  why the option  is getting disabled in your test and you have a valid support agreement  contact Ixia support

General: How to modify the maximum number of allowed IxLoad instances on IxLoad client

        By default you can open maximum 2 IxLoad GUI or 4 IxLoadTCL instances  from an IxLoad client at a time
Sometimes you  may need more than 2 open GUIs in the same time. To change this setting open IxLoad GUI-> On File tab-> select Preferences and check the number  of allowed instances:

      If you need a bigger value than 15 or if you use a version of Ixload prior to 6.0  you will need to modify the ixMachineOtions.ini file
The ixMachineOptions.ini file is created the first time you start IxLoad, and is stored in the following directory on the IxLoad client PC:
Windows XP:           C:\Documents and Settings\All Users\Application\Data\Ixia\IxLoad\<version>\
Windows 7/2008:      C:\ProgramData\Ixia\IxLoad\<version>\


****A GUI session requires 2  TCL IxLoad instances so if you need 20 GUI sessions  set  maximum_instances=40 in ixMachine.ini