As designer says, if everything else is equal, the discharge end is generally preferable.

A couple of reasons:

1) You would normally take the thrust from the screw out at the discharge end so the flight is in tension and it is preferable to locate the drive at the fixed end, particularly if there is any temperature involved which can result in thermal expansion.

2) It is normnally cleaner at the discharge end, there will normally be equipment above at the inlet end and any spillage will fall on the drive assembly and and give problems with chain drives, etc.

Having said that, layout and access sometimes make it much more approriate to locate the drive at the inlet end. In most cases, the effect on performance will be marginal. ■