Minecraft Singleplayer FPS issues?

Recently since the 1.7 minecraft update minecraft single player has been acting up the frame rate drops to 15 FPS and will not go any higher if i turn my fog to tiny it still won't go higher however if i join my friends server the FPS goes up to 70 i downloaded optifine and turned everything to the fastest settings and still no avail
is there anyway i can get the single player to work

my computer specs are

CPU: AMD sempron 140 @2.7 Ghz
GPU: AMD HD7470 1GB gddr5
RAM: 3GB

sorry if i misspelled anything

Added (1). i have my max FPS set to unlimited

M Garcia

The Specs aren't looking bad…
In any case, do you have the FPS limit at 15 for single player? Because that's the only thing I could think of that would keep it at 15 FPS…
You should be able to change it on Video Settings at the top

Benni