I have no virus scanner, it's virtual machine.
I mean that in the same ENV and test condition, the windows version of 2.2.30 is 10x faster than the windows version of 2.4.38.
I'm reading the source code of 2.4.38 now, and i found the thread pool related code(daemon.c tpool.c connection.c) has changed a lot between 2.2.30 and 2.4.38.
It's may be the reason, i'm not sure...

2013/12/23 Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>
>>> Ferne Quinlan <shimmy886@gmail.com> schrieb am 18.12.2013 um 15:04 in Nachricht
> Thanks for your reply.
> But my test result is:
> 1. OpenLDAP 2.4.38 on Windows is about 10x slower than it on Linux. Not 2x
> nor 3x as you say.

Before comparing cats and dogs: Do you have a virus scanner on Windows that does on-access checking? On Linux also?
Did you try to disable the virus checker during the test?

> 2. OpenLDAP 2.2.30(the previous version we used) on Windows is almost the
> same fast as Linux.
> That makes me confused. Is there something related changed from 2.2.30 to
> 2.4.38?
> Or there something wrong i do with 2.4.38 on Windows?