There is a new folding@home Gromacs core that will be generally available next week. It is enhanced for all machines and I'm sure you'll be impressed with the results, especially on G3s. Currently, it's only taking 37 percent of the time to process a work unit on my dual G4/800. 83 minutes per percent became 33. Anyway, you can download it, earlier than would happen automatically, by removing FahCore_78.exe from the usual directory.