We will  need more information to properly answer your question.  What thickness of plate, what voltage and amperage, and what size of a bead are you trying to produce.  Naturally you can run faster in the flat and horizontal positions than in vertical up or overhead.

I gave this answer on another post and I think it still applies here:

You should get a copy of the Lincoln Electric Arc Welding Procedure Handbook.  That has just about anything you might need for info on travel speeds.

Adding to that:
Another option is the free literature from various electrode manufacturers - they give the optimum ranges to use.  And of course you can  go out and burn some rod with someone timing how long it took to weld how many inches.