What leads you to believe the response payload size is the culprit?
It will be hard to offer specific guidance without reviewing your specific scenario via Webex. I believe it is worth opening a ticket so the support team can look at this with you.
In the meantime, can you help us with a few more details?
- What version of DevTest are you using?
- Which OS platform?
- How are you determining the 500ms response? (e.g., using DevTest log file timestamps or measured by the consumer application)
- What logging level are you running?
- Does the response have a high number of magic string or magic date values?
- Are there any customizations, use of custom JARs, or non-OOTB steps in the VSM?
- Are there Match Scripts in the VSI?
- Is this a functional or performance test?