well.. maximum settings are fine. relatively of course.
things that matter:
Java version and if it is 32 or 64 bit.
how much memory is being used.
Detail level might affect lower end GPU's to a degree.
and since it is in Java, anything on screen will reduce FPS a LOT.
especially half transparent blocks like stairs and slabs. Trust me, 108000 stairs will cause ANY computer to drop to single digits if looked at. (especially if they are next to each other causing computer to recount if anything behind other blocks will be visible.)
Thanks for the help bro. I have taken a look at it more and I see what you are saying. My computer runs about 350 frames on max settings now. Thanks for the help.
thus, amount of chunks loaded/shown help a lot on the fps issues.
My computer is quite similar to yours, only bit weaker CPU/GPU and I can get 100+ on average all details maxed out. until load happens (new chunks on view or other things) which drops it quickly to 40's.
Also some say that using mod like optifine can sometimes help a lot since it handles drawing stuff a bit differently than minecraft.