Ftb massive fps drops

[guy portal]

hey, im playing ftb and im running it smooth on a hosted server with my friends
i get like 600 FPS and after 5 minutes of playing
boooommmm
0 fps like a picture show...
and i quit the game and go in again and its get stable again for 5 minutes
im playing these settings
render distance = normal +32
graphics = fast
smooth lightning = off

and my computer is
cpu = Intel Core i5-2500K CPU 3.3GHz
ram = 4 GB
64 bit windows 7
gpu = Nvidia Geforce GTX 550 ti

thanks for helping ill be graceful

 

[Ashzification]

Please read below. Please be sure to read all of the info available in the 2 articles.

Spoiler

Please follow these steps exactly: http://desk.feed-the-beast.com/index.php?/Knowledgebase/Article/View/9/0/basic-troubleshooting
This is to rule out any issues with your setup. Please also read the extra info at the bottom of the guide, and apply all applicable suggestions.

Please post your complete client-side (launcher) console log in debug-mode to pastebin.com and link your paste URL here.
To find your logs and prevent them from expiring: http://desk.feed-the-beast.com/inde...29/1/what-log-do-you-need-where-can-i-find-it

Start with the above posted instructions. This way, we can rule out any possible issues with your setup effecting your FPS.
If the lag still occurs, try reducing your video settings to Fast, and not using a texture pack.