Highest FPS?

Also, frame rate depends largely on what is being rendered; to make a fair comparison you'd want to follow a standard setup, like the one described on the Wiki's Hardware Performance page (to compare versions before 1.7 you'd want to create a world in the older version first, then use it to test later versions). Even on my old computer, which was below the current minimum system requirements (but not the ones for 1.6.4, the version I used), I managed to reach 1000 FPS when looking up at minimum settings on a default Superflat world (ironically, Optifine only gave me 600, while under normal conditions it is similar with smoother FPS).