Since you have tried all of the standard browser items it is hard to make suggestions without knowing what type of computer you have, what video card, what programs you have that may be running in the back ground etc. Another thing is how bad is the meter stuttering? With some computers there may always be a slight stutter. One possible reason your older computer may do better is the video card may paint pixels faster than the new one.
You mention Game Booster, did you use the configure feature to turn off the unnecessary processes & items that are running in the background?
One of two other things you can try is either use CC Cleaner to shut down more start up items or type msconfig in your Star/search box and uncheck startup & processes along with items that you don't need. But you need to be careful not to shut off necessary ones.
Do you have other screens open or other programs running when you are playing the game? Some computers can handle that others can't.
This game uses very little memory and a LOT of most computers CPU % which fluctuates from low to high. If you downswing during those fluctuations then the meter can stutter. How much depends on your system.