TSVN slow merges (help!)

Hi,

Some of you may have read reports that TSVN is twice as slow when doing
a merge than the svn command line client (RC9 from open.collab.net).

I can reproduce this easily: the build script of TSVN also builds the
command line client, so simply comparing that client with the one
installed from open.collab.net shows the same effect.
I've used the tool "timethis" to measure a simple (but useless) merge:

timethis svn merge -r11761:11762
http://tortoisesvn.tigris.org/svn/tortoisesvn/branches/1.4.x
d:\development\SVN\TortoiseSVN --dry-run --accept postpone

This results in a merge time of 2 min 37 seconds with the rc9 from
open.collab.net, and 5 min 17 seconds with the command line client built
myself with the TSVN build scripts.

I've also recorded the network packets with WireShark: they're identical
for both clients. The only difference is the time between recorded packets.

Here's what I tried already:

* disabled ipv6 support
* disabled serf (only linked with neon)
* tweaked several compiler optimizations
* tried different defines to tweak the build
* tried different values for the win version defines

Of course, after every little tweak I did a full rebuild just to make
sure that the tweak was used.

But: nothing worked. I still get more than 5 minutes for the merge with
my build.

As a last resort, I ditched the TSVN build script and used the official
Subversion build script and built the command line client with that. But
even *that* did not help! It's the same as with all my other builds.

The only difference that I can see (apart from the time required for the
merge) is that the client from open.collab.net is built with VC6, and
I'm using VS2008 for the build.

And now, I don't know what more I should try. I've been working on this
for two days now and I'm out of ideas. So if anyone of you has an idea
why this could happen, please, please help me!

Stefan

-- 
        ___
   oo  // \\      "De Chelonian Mobile"
  (_,\/ \_/ \     TortoiseSVN
    \ \_/_\_/>    The coolest Interface to (Sub)Version Control
    /_/   \_\     http://tortoisesvn.net