BUG #2906: slow windows network performance

The following bug has been logged online:

Bug reference: 2906
Logged by: Adriaan van Os
Email address: postgres(at)microbizz(dot)nl
PostgreSQL version: 8.1.4
Operating system: Windows XP
Description: slow windows network performance
Details:

Somehow, native Windows networking is very slow. Extensive tests show that
transferring large amounts of data from a Windows XP server to a Windows XP
client is up to 60 times slower than sending the same amount of data from
the same Windows server to a Mac OS X client with "comparable" (Intel)
hardware. This is true when working with libpg synchronously as well as
asynchronously. The probable cause is PQconsumeInput and the native Windows
networking and/or the wait-for-single-object-or-so routines that it calls.

This has been tested on a range of machines, including a brand new
out-of-the-box Windows XP machine. Processor usage during the data transfer
on the Windows client machine is very low, so obviously, the client machine
spends most time in a wait-for-nothing state.