Running OpenEx at high data transfer rates. Optimize to avoid errors

Tech Note: TN0237
Product: OpenEx
Version: All
Date Added: 2007-02-02

Issue

When operating OpenEx at higher data rates (generally 16 channels or more) measures should be taken to improve overall system performance and efficiency. The system is optimized via modifications to the OpenEx project and its Stores and by terminating unnecessary applications running on the host PC.

The following list of guidelines can be used to optimize system performance.

OpenEx

  1. In OpenWorkbench, set the Cache Delay preference to 6.0 seconds and ensure the Flush read when overload preference is NOT enabled. To check or modify these values, click File → Preferences in the OpenWorkbench window.

  2. Turn off all unnecessary scrolling plots within Workbench. To turn off individual plots, right-click the plot and click Hide.

  3. Run each device/RCO in your OpenEx project at the lowest acceptable overall sample clock rate. For example, if you're collecting EEG type signals you should set the device sample rate to no more than 6 kHz.

  4. Ensure a reasonable sample rate is being used for each Store in your project and use 16-bit or even 8-bit data for Stores whenever possible.

  5. Remove any redundant data Stores. For example, if you are storing the full 25 kHz bandwidth signals in your single unit collection project, there is no need to also store a band-limited LFP version of these sample signals.

  6. In Workbench Setup → Polling and Performance, set the Target Bus Loading to 80%. This places more priority on storing the data versus distributing it to other applications, such as OpenController.

Operating System

  1. Turn off unnecessary applications including

    1. Background applications like anti-virus, firewall and spyware detection tools

    2. Services that run in the background even if you do not have the program open, including Superfetch, Prefetch, and search Indexing.

  2. Turn off any automatic update features.

  3. Avoid launching applications once data collection has started in OpenEx.

  4. Avoid doing other tasks on the collection computer while it's running OpenEx (like accessing the Internet)

  5. If you have USB or the Wired Gigabit interface, consider upgrading to the Optical Gigabit Interface.

If you need assistance with any of the above design guidelines, please contact TDT technical support.