Different nightly's

Since the table form nightly is available, I get 2 nightlies for LT. And the resu7lts can be quite different. (One has no diff, the other has hundreds).
How come?

They use different data, one much more than the other. This is the larger one: Index of /regression-tests/via-http/

Okay. The differences are very large indeed. The runs start at different times, so a submit in the evening might cause the differences, or just the size?

Both usually work on the same snapshot (downloaded from Index of /snapshots/), so differences should just be caused by the difference in input data.