Depends on the year/model.
The early R-1830s were rated at 2400rpm (a few prototypes may have been run at 2300rpm?) then they went to 2550rpm and then to 2700rpm for take-off and 2550rpm for max continuous. Last models were good for 1350hp at 2800rpm for take-off.
The R-1820 started at 1900rpm of direct drive and 1950rpm for the geared engines in 1930, went to 2100rpm take-off and 1950rpm M.C. (max Continuous) then 2200rpm T.O. and 2100rpm M.C. After going through the E,F,and G models you get to the G100 series which was good for 2350rp for take-off (mostly), the G200s were good for 2500rpm (again, mostly) and the "H" series engines went 2600rpm for 1300-1350hp, 2700rpm for 1350-1425hp, 2800rpm for 1425-1525hp (post war engines and using up to 115/145 fuel) most of these last engines went about 1400lbs, the 1900rpm engines could be as light as 850lbs with direct drive.
The R-1830 was supposed to be smoother and transmit less vibration to the airframe. It was smaller in diameter and had less frontal area.
Since each type was built in dozens of different models with different crankcases, cylinders, bearings and what not it gets very hard to generalize about the series as a whole.