When analyzing performance data of sending multipart/form-data requests, our performance team noticed that RESTEasy was writing data to disk when the payload size was greater than 1024 bytes on the server or greater than 1MB on the client. This had a huge negative impact on performance when sending/receiving payloads larger than the default threshold.

These settings ought to be configurable so that users can specify the limit of data used in the process before writing to disk.

I'll plan to submit a pull request with this capability shortly. Thanks!