Decrease your render distance to very low and try using a texture pack which helps fps also you must alter the settings in optifine for better performance I recommend you to watch this and it may help you,
If you get a static 60 fps, try to disable/enable Vsync(Vertical Sync) on options menu. i don't see javaw.exe
Don't double / triple post so much, ty The best way to improve is btw this: Spoiler: Click here for le secret
You have to launch minecraft (the game not the launcher) Then you hsould see javaw.exe It should be in the processes tab
Go to settings of optifine and find the one which says lazy chunk loading and enable that ALSO watch the video
Optifine is a mod, but the developers made it so that you don't have to do anything more then downloading the file (which is great imo, just press a button and you are done) .