Since the Gromacs core arrived, I've noticed that the complexity is a bit much for my G3/400 and it strains to keep going with the most complex of them. e.g., 4 hours 10 minutes per percent where the same WU can achieve a rate on my dual G4/800 of 1 hour 23 minutes. Since the G4 often gets Tinker units at the same time, I swap them.
You can copy the work folder, unitinfo.txt, and queue.dat from the folder where your data is held to put on the opposite machine.