well, new here on the forums (but not to mods glitching out and FTB/technic in general) but in previous versions if this has been persisting for ages on end I've never had a problem, but a few days ago it started up just like everyone else. I turn on for 10 minutes at best and get lag. Then gradually more lag, until about 10 minutes more and I'm down to freeze frames and then it either crashes with a permgen error of some kind or a general out of memory crash.
and you know what the moment was when it all started? When I tried to use buildcraft engines to extract stuff from barrels to and from a cargo manager connected to a wood farming cart I had going in my flatlands test world. Even the 5 turtle strong mob grinder I had already built using a nooby startup melee loop didn't cause terrible lag until of course the 10 or so brain jars ate all the EXP and the turtles got loaded full of loot and began leaving crap all over the place which is predictable.
Ever since said barrel lag out I've been getting the lag crashes. I've tried updating forge to the latest, optifine ultra 5, removing chickenchunks, updating chickenchunks and other possible world loading mods and still nothing. Sometimes I might get a fair game of half an hour before it starts acting up again but thats about it. All the time it's memory overloads or permgen space or something glitch.
Before that test that began my hunt for mod updates and attempted fixes I was I was able to have games of 3-4 hours long on my server with a buddy using my same pack ("my same pack" since it's mindcrack but with a few other additions I can't go without) ... Hell even the server crashed itself at one point when I tried to use barrels to store surplus materials so lets just say it's being a real douchenozzel and it seems to cause major problems when theres a certain mix of stuff going on. What that mix is though, I'm stumped.