I have run 50 times the rfcp of a data file (+ possible 
compression/uncompression) on the batch system and then mediated the total 
time of the operation. The original size of the dat file was 3.29 GB that 
was reduced to 1.58 GB after gzipping, and to 2.06 GB when using lzop with 
"-1" option (= compress faster). Lzop is available from 
http://www.lzop.org/.

 The average times are:

---------------------------------------------
Operation		Compr'd	File	total
			File?	Size	time
---------------------------------------------
cp local->CASTOR	No	3.29GB	 63s
gzip, cp loc->CASTOR    Yes     1.58GB  237s
lzop, cp loc->CASTOR	Yes	2.06GB   91s

cp CASTOR->local	No	3.29GB	 67s
cp CASTOR->loc, gunzip  Yes     1.58GB	 77s
cp CASTOR->loc, lzop -d	Yes	2.06GB	 65s