SAVF? Compressed or not?

["Ryan Hunt" <ryan.hunt@xxxxxxxxxxxxx>]

I have always been told that a save file (CRTSAVF) is a lot like a windows
zip file. Is this true?  The reason I ask is that every Sunday we back up
our production data libraries to save file.  Now, I've totalled up all the
files (that reside in the save file) and they amount to 42.5GB of data.

Here's my confusion...

In iSieres Navigator, the "Size" column shown while browsing the IFS shows
my save file to be 3.03GB.  When I select the file and view properties, the
save file shows up as 41.74 GB.  If I do a WRKOBJ on the object and views
its file size, it again shows 41.74 GB.  I have also confirmed that the save
file is taking up 41.74GB on my DASD.

So, what's up with the size discrepancy?  Also, should this file be
compressed or not?

Thanks in advance. RH