High CPU load and slow performance on NT/W2K

[Petter Österlund]

Hi!

I am experiencing very high CPU load and long update times using
rsync.exe on NT/W2K. The versions I have tested on NT are; 2.4.6, 2.5.1-2
and 2.5.5-2. Cygwin1.dll version 1.3.10. They all show the same kind of 
problem.
Is there anything that I might have missed, or is the perfomance not 
better than this?

On the other side of the transfer I have used both NT/W2K, Solaris and 
Linux.
I have been executing the the rsync command on NT/W2K as well as on the Unix
hosts. The outcome is the same; The NT/W2K machine gets loaded to 100%.
Transfering between the UNIX hosts are no problem. The machines are on a 
100Mb/s LAN.

I am doing an update of a 15 MB text file, like this:
(fyrsol2: Solaris2.7, bserv: Win2000)

-----------------
fyrsol2 # touch x.txt ; time rsync-2.5.2 -avv --progress x.txt 
bserv::tooltest
rsync: building file list...

rsync: expand file_list to 4000 bytes, did move
rsync: 1 files to consider.
x.txt
   15806883 100%   10.27MB/s    0:00:00
total: matches=10081  tag_hits=10081  false_alarms=0 data=0
wrote 40481 bytes  read 60542 bytes  8081.84 bytes/sec
total size is 15806883  speedup is 156.47
1.50u 0.39s 0:12.15 15.5%
--------------------

Notice the transfer time is 12 seconds! (The 10.27MB/s reading must be 
false).
During this the CPU load of the NT/W2K host is 100% for at least 6-8 
seconds.
(The file can be transferred in 1.5 seconds using FTP!)

But now to the realy funny part; If I change the command by adding a -z 
option
I get an unexpected performance gain:

----------
fyrsol2 # touch x.txt ; time rsync-2.5.2 -avvz --progress x.txt 
bserv::tooltest
rsync: building file list...

rsync: expand file_list to 4000 bytes, did move
rsync: 1 files to consider.
x.txt
   15806883 100%    3.67MB/s    0:00:00
total: matches=10081  tag_hits=10081  false_alarms=0 data=0
wrote 158 bytes  read 60542 bytes  9338.46 bytes/sec
total size is 15806883  speedup is 260.41
4.23u 0.27s 0:06.03 74.6%
-------------

The update now is done in half the time and the CPU load of the NT/W2K host
is only touching 100% during a very short time at the end of the update.

Any sugestions?

/Petter