Errors or performance issues when sending files larger than 10 MB


  • EFT Server version 5.2.15 and earlier
  • Secure Ad Hoc Transfer (SAT) module version 1.7.2 and earlier

NOTE: This issue is resolved in version 2.0 of the SAT module, for use with version 6.x of EFT Server. For performance reasons, if you are sending files larger than 10MB, you should make this change so that the memory usage of the IIS server does not spike and degrade overall system performance.


The Web browser returns an error when attempting to upload large (~1GB) files with the SAT module and the Windows Application Event log indicates that ASP.NET threw an "Out of Memory" exception.


Change the "requestLengthDiskThreshold" value in the web.config file to 1024.

To change the value

  1. Open the web.config file in a text editor (such as Notepad). (By default, the web.config file is installed in C:\Inetpub\wwwroot\EFTAdhoc.)

  2. Press CTRL+F. The Find box appears.

  3. Type requestLengthDiskThreshold, then press ENTER.

  4. Change the value after requestLengthDiskThreshold to 1024. For example:

    <httpRuntime executionTimeout="600" maxRequestLength="2097151" requestLengthDiskThreshold="1024" useFullyQualifiedRedirectUrl="true"/>

  5. Save the web.config file.


The "requestLengthDiskThreshold" value in Web.Config is stated in MSDN as being "bytes," but really it is "kilobytes." As a result, the SAT default deployment value of "1048576" (which is 1024x1024) does not resolve to "1MB"; instead, it is off by a factor of 1024 and therefore is 1GB. This means that IIS/ASP.NET will, by default, attempt to read the first 1GB of the upload into memory, not just the first 1MB while the rest is streamed to a temporary location.

Also refer to #10484 - HOWTO: How do I tell IIS to transfer larger files with the SAT module?