Why am I getting really low frames on FTB?

[Shadowgun]

Okay, so I have recently been getting a max fps of around 20 fps.
Before all of you say I have a bad computer, here are my specs:
i7 3770 @ 3.4 Ghz 3.8 Turbo
16 gb of corsair vengence ram
Geforce GTX 660ti
Etc, etc.
Now Im 100% certain that FTB does make people have low frames (A lot of my friends can barely play at 4 fps, while they get like 60 on regular).
My problem, however, is that when I first started playing FTB I was getting close to 200-300 fps, but how am I now only getting 20?..

 

[lavarthan]

FTB includes a lot of mods it is only natural that the fps would drop. There are a few things you can do to possibly help.

First make sure you have FTB installed the recommended way. Follow this guide exactly.
Second get Optifine Ultra and enable multi-core CPU support. You want 1.4.6_HD_U_D5 Click on the older versions spoilers button under the Ultra version for 1.5.x
Third if you are still experiencing fps issues try this knowledge base article about it.