Whenever I play ftb on minecraft, java uses up like 3,000,000 K memory in the task manager and my cpu and ram are at 90-100%. I don't have any other programs open. I also only have around 20 fps while playing. My computer has 6gb of ram and an AMD Athlon II X2 250 Processor. I don't know what to do because I can't play with 20 fps. Someone help, I will chose a best answer.
Java taking up too much ram (Minecraft)?
Have you contacted minecraft support and/or posted in their support thread?
http://www.minecraftforum.net/...ms/support
https://help.mojang.com/...ojang.com/
could possibly help while you wait for a response here
Actually this is all natural. FTB, Hexxit, Techit or any other packs that are out there eats a lot of your computer. This includes the java eating up your memory. The people who runs this kind of packs always have a very power gaming rig.
Usually the rigs are in Windows 7/8 64bit, i7 GTX 700 series or TITANs, any powerful CPU/GPU coolers and a big RAM and I mean BIG. Powerful fan and PSU to hold things together.
from what i see from the specs you've given, you'll definitely have issues cause your specs aint too powerful to run FTB in its full potential.