I'm running over several terabytes and on the 5k images I've done so far (3.6GB), the compression has been 0.78x, which is damn good for lossless compression!

I'm running over several terabytes and on the 5k images I've done so far (3.6GB), the compression has been 0.78x, which is damn good for lossless compression! EDIT: 17GB now (my server is kinda slow) and it's still holding at 0.78x.