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