Socket communication using the loopback address will intermittently encounter a five second delay
On a multi-processor computer that is running on a Windows version listed in the Applies To section, recv() sometimes waits five seconds using the loopback address (127.0.0.1).
- Repeated large transfer data more than 64KB to 1MB.
- Using Loopback address (127.0.0.1).
- Multi-processor computer.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB2020447.