I much prefer two on the same screen, the top being the current stage (1 of 5 stages) and the second being the progress of this stage (100 of 1000 files). It's then obvious there's are 4 stages left and that the current progress of files probably does not reflect the progress of another stage. And to be fair some people do that by just resetting the bar so it goes from 99% to 1% and you then swear at it because how is that helpful. 2 bars on the same screen simple to know where it is and if it really is stuck at 99% of stage 5/5.