EDIT: The online 7424 manual says that speed 1 is 2500 OPM, while speed 6 is 6000 OPM...so by my rough calculations 3000 OPM is approximately speed 2, while 4000 OPM is approximately speed 4.
The G100 is the same unit as the PC 7424 or 7336. The Current UDM is the same machine and the data presented in the following link were for the original UDM and not the current UDM.