Consistant Lag Jumps

[Sisrace]

Hi, i've played ftb now with my friend on a server, Recently i started getting some pretty heavy lag jumps. It feels like if you are running on 2 blocks grass and 1 block soul sand in a row so you go fast, stop, Fast, Stop, Fast. You get the idea.
Its really annoying especially considering my computer specs.
If it was on my old computer i wouldnt care because that thing lags no matter what. but this computer ran buttery smooth until 2 days ago, 2014-08-02

Specs:
16Gb ram
64Bit Win 8.1
AMD FX 8350 4Ghz 8 Core
ASUS GTX 660 DirectCUII OC
1TB SSHD
2TB HDD where i currently have my Virtual ram setup for windows..

 

[Shevron]

How much RAM have you dedicated to Minecraft? Did you set it up in the launcher?

Default is usually 1GB which is far from enough. You got to push the slider further. I say 3GB should be enough for any modpack.

 

[Sisrace]

I was dedicating 4gb ram, But i took it down to 3Gb wich solved the problem but i still dont get as much smoothness as before. i still got som frame issues but the extremely annoying lag jumps are gone