Fps Drop

I get huge continues Fps drop in minecraft, When in the newest snapshot my minecraft drops to 20 - 10 Fps depending on the settings. but never seems to go above that much.

When I got back to that same world (same computer enviroment) but then using 1.6.2 I get my old Fps back which is around 100 - 50 Fps.
and this is on better settings then using the snapshot.

I have included in text files both Console output for each time loading a version. and loading the same world.

I also included a gallery on imgur, which displays the settings I used for both version and the result of that.

I do know the snapshot version says 13w38b, but I have tested this in the 'c' snapshot as well and same result though a little note:

when I make the actually window of minecraft smaller on my screen to say half of my screen, the fps goes up. and turning advanced OpenGL off increases my Fps with about +10

The Gallery: http://imgur.com/a/bW4nQ

I know this bugreport might be a duplicate but I was not sure, since I have no clue what is actually causing this preformance gapt. and thus I don't know if what I have done is similiar to some ones else bugreport.