Windows .jar Have big problem with in-game lag (un-playable) - FTB Unleashed

[Fr0sted]

Hello FTB community.

I'm trying to play this epic modpack (FTB Unleashed) but I have a big problem with lags.

My computer specs :
CPU : Intel Pentium G620 @ 2.6GHz
MOBO : ASUS P8H61-M LX2
GPU : ATI Radeon HD 5670 (Driver v13.4)
RAM : 4GB DDR3
OS : Windows 8 Professional - 64bit

I think its a nice one PC but why I have lag.
Normal RAM usage (while on internet, etc.) is 32% but when I start FTB-U it is 98% (I close everything but no help).

I have both 32&64-bit Java installed (Oracle Java) and have 1.5GB in FTB Launcher Settings.

Now, I uninstalled both Java and waiting for someone to help me.
What Java (developer/version) to install and how to setup FTB Unleashed to work without lag on this PC?

Please answer and thanks in advance

 

[UniZero]

Only have the 64bit install of java not both. Try adding the JVM Arguments from this thread. To add them open the launcher and go to options then advanced options and copy and paste the text into the "Additional Java Parameters" box.

You also may want to consider adding more memory, because the minimum to use the JVM arguments is 4gb, to your system unless it is a laptop you are using.

Your cpu is also not the greatest because it is a low end model.

Unfortunately you will not be able to setup it up without lag / fps drops because it will happen eventually on almost any system.

 

[DZCreeper]

Uninstall 32 bit Java and tell FTB to use 2 gigs of memory.

Sadly, its going to be almost impossible to get good FPS with that setup, those parts are fairly low end.