teststand become slow and slow

[sean_tan]

I edit a sequence without connect any instrument.just run in demo. and I set one action loop 1000000 times.but about  after 20 min.I find Teststand become slow and slow,How can I solve this problem,

[~jiggawax~]

What is your memory doing?  Basically everytime you add to the ResultList you are adding to the memory.

[Evan P.]

Sean,

Jigg is right on. Unchecked memory allocation can cause degraded system perfromance in any environment. With TestStand, each time a step executes, by default, the step's Result container is copied to the ResultList for reporting later on.  This list will, again, by default, persist until the execution completes. In the case of large interation loops, memory can be consumed quickly, which will eventually cause a slow down in your system's overall performance, since your operating system's resources are being monopolized.

The following settings are a few of the important settings pertinant to TestStand memory managment:

• Record Result Property: can be disabled if a step's results are unimportant for reporting 
  • Select a Step's Step Settings Pane»Property Tab»Run Options and modify the Record Result option for a local change.
  • Choose Configure»StationOptions...»Execution Tab and modify the Disable Result Recording for All Sequences option for a global change.
• On-The-Fly Reporting Option: when enabled, can provide long-term, static memory usage.
  • Choose Configure»Report Options...
• Discard Results... Option: can be used in conjunction with On-The-Fly reporting for lean memory usage.
  • Choose Configure»Model Options when using any provided process model.
    
• Conserve Memory... Reporting Option: can be used to automatically, periodically purge memory used by reporting objects.
  • Choose Configure»Report Options...

Check out the Developer Zone Tutorial: Best Practices for Improving NI TestStand System Performance for a more detailed and inclusive look at decisions that impact TestStand performance.

Message Edited by Evan P. on 10-16-2008 01:02 AM

[PeggyC]

I am going to use TestStand to implement test sequence also, and I am also have the same concern, because the test sequence could have more than 2147483648 steps.  Is there any recommandation on how big of the computer memory should be?

Thanks

Peggy

[Dennis_Knutson]

What sort of test sequence is going to require that many individual steps? I would not want to hazard a guess on how much memory you would need.

[PeggyC]

This number is from previous somewhat similar program.  This number includes measurements, stim cmd, action, and control steps.  The initial thought when I ask this question is in the case if everything is going to be recorded.  The actual measurement maybe in hundreds (say 100-300~).  I think, the current computer configuration has 512MB of RAM on Windows XP, but there is also a debate on whether or not it should go up to 1GB or more.  From the description of how the recording is, it sounds pretty memory demanding.  So, it makes me questioning on whether or our current computer configuratoin has sufficient RAM.

[Dennis_Knutson]

The recording is as demanding as you make it. As mentioned, you can disable the recording of results and I suspect you will have to do that for the vast majority of the 2G steps. You could also modify what data is saved.

In any case, 512MB is pretty low and I would recomend at least the 1G. Memory's so cheap that 2M would also be reasonable.

[PeggyC]

Do you where I might be able to find a justification?!

Thanks.

Peggy

[Dennis_Knutson]

See the NI recomendations. For my applications, each sequence has roughly 1000 measurements. We run the parallel model with 2 UUT's so we just doubled the recomended RAM. The cost of the extra RAM was buried in the noise compared to the cost of the pc itself and measurement hardware.

[PeggyC]

Thank you, Dennis.  What you said is very good info.