Performance Recommendations

Our recommendations for setting your performance preferences.

Modifying the performance preferences can help improve your FlowJo experience if you have sufficient hardware. Below are the general recommendations for performance preferences settings on Mac or PC with varying amounts of RAM. We recommend having at least 4x the amount of RAM as the size of data being loaded into FlowJo at the same time for analysis.

How to Modify Performance Settings in FlowJo v10

If you have sufficient RAM installed, then the default performance settings may be increased to improve calculation speeds on large data sets. This can be accomplished in two steps:

Step 1 – Allocate more system memory to FlowJo :

  1. Click the Heart Icon in the top left corner of a FlowJo workspace window.
  2. Choose Performance in the bottom row of the Preferences window that pops up.
  3. Within performance Preferences
    • Set the Max Sample Cache Data size – This is the maximum amount of FCS data that can be stored in memory. If exceeded, some files get booted out of memory. We suggest to set this to ~1/2 times the total RAM installed on the computer. On a PC, the default value here is set to work for a computer with minimal installed RAM (default setting is 7372 mb), and can be adjusted accordingly if more RAM is installed.
    • Set the Engine Request Cache size – This is the number of request/response pairs that FlowJo keeps in memory so it does not have to do the work again.
      • If 32GB of RAM is installed, set this value to 4000.
      • If 64GB or RAM is installed, set this value to 8000.

Step 2 – Allocate/allow the FlowJo client to utilize more memory:

Step 2 Mac Instructions:

On a Mac, this is accomplished by modifying the info.plist file within the Mac Application Contents folder. This modification should only be done if the user has 128GB or more RAM installed. To do this:

  1. Quit FlowJo
  2. Navigate to Applications/FlowJo, and Right Click on the application, then select Open Package Contents
  3. Open the info.plist file in a text editor program. Scroll to the bottom of the file and find the line of code: <string>-Xms512M -Xmx32G</string>
  4. Modify the line of code to increase the total amount of RAM that can be utilized for the Java Virtual Machine environment.
    • If 128GB of RAM is installed, <string>-Xms512M -Xmx64G</string>
  5. Save the change & restart FlowJo

Step 2 PC Instructions:

On a PC, this is accomplished by modifying and replacing the FlowJo10.lax file, which is located within the FlowJo 10 program folder.

  1. Quit/exit FlowJo
  2. Navigate to the FlowJo 10 Program folder. The default install location is C:\Program Files\FlowJo 10
  3. Save a copy of the FlowJo_V10.lax file on the desktop
  4. Open the FlowJo_V10.lax file in a text editor program
  5. Search for/Find the following line of code: lax.nl.java.option.additional=-Xmx8192M
  6. Modify the line of code to increase the total amount of RAM that can be utilized for the Java Virtual Machine environment.
    1. If 32GB of RAM is installed, the line can be modified to read: lax.nl.java.option.additional=-Xmx16384M
    2. If 64GB of RAM is installed, the line can be modified to read: lax.nl.java.option.additional=-Xmx32000M
  7. Save the change
  8. Replace the existing/original FlowJo_V10.lax file with the modified one. (Requires admin privileges)
  9. Restart FlowJo

Please note that many reports of poor performance can be traced to analyzing data off of a network or cloud based storage drive. These services can cause serious issues if not managed properly. We always suggest bringing data to a local drive for analysis, then saving as an ACS and moving that ACS to the network or cloud drive for long term storage and archiving.

Explanation of all Performance prefs

Explanation of all Tools prefs

Explanation of all prefs