Im running on MultiMC as someone told me to add a few parameters and see if the lags get better or not, so the parameters is:
"-d64 -server -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:MaxGCPauseMillis=40 -XX:GCPauseIntervalMillis=150 -XX:MaxPermSize=512m -XX:+AggressiveOpts"
So the allocation for it is 4096Mb right now.
I tried to allocate 16GB and i tried all between 2-4GB.
Yes, this was from me, and helps gut the general lag from ftb, but it doesn't fix all problems.
Quite honestly I don't have a great computer atm, but I still get better fps than you. You want to know why? Because I pay attention to what problems occur for people and solutions that at least some what alleviate them.
Like how turning off clouds can give some users a huge fps boost.
Like how the 1.4.7 packs have memory leaks that can destabilize your world (and fps) and placing spot loaders to prevent them and increase some users fps.
Like knowing how some optimizations in 1.5.x can triple some users fps over 1.4.x
Like how learning how to tune your Gfx card for java can jump some users fps.
Like how a change from java7u9 to u21 can up some users fps.
Do you see the trend? It's "some users" not "all users."
Everyone will have different suggestions for you to try. Some will work, some won't. Possibly none may, or you may need a specific conjunction of things.
But if you act like the beginning of this thread, no one will offer what worked for them and you will be stuck playing at low fps.