[tjcinnamon]

I recently started using this program. It's great. I imaged a few drives at work. These were 70GB drives that only had 15GB of data. When I imaged them they only ended up being 8GB.

Is there a way I can tell before I image a partition with this program, how big will the image be after compression? Lets say I have 150GB of data is that depended on the kind of data?

Thanks,
JOe K.

[FishBowl]

Definitely depending on content and packer routine used
Same as with archivers.

As an example, big differences can even show up on the very same file type:
I am recording from DVB-S frequently.
Normally the resulting .mpg files can't get compressed noticeably, as they are already heavily compressed inside.
BUT if the source is a truly digital test screen (like those I am using for TV repair), a good engine like ace or 7zip might compress to far less than 10%.
A special flicker test sequence I've created with mute audio compressed from >100 MB to around 100 kB.
Forget zip on this...
A matter of packer intelligence.

So no way for a realistic prediction.