Jojash

I may have found it myself, actually, http://forums.technicpack.net/threads/low-fps-in-tekkit.12688/ After following the steps in Stathol's post I don't seem to be having frame rate issues anymore! Again, thank you all very much for all your help! :)

I do...

Thank you very much, I eagerly await your suggestions. :)

I am using 64-bit java, it's the only one I have installed. I've tried switching to the default Minecraft texture pack and that's made no difference. I'm not sure what you mean by Optifine, but if you can point me in the right direction, I'll certainly give that a go, do you have any suggestions as to what I should be tweaking?

That has helped somewhat, it doesn't seem to lag after idling as much, but it does still have quite bad lag when I'm looking at jungles.

So, recently, I've been playing Tekkit and I seem to be experiencing some serious FPS issues, sometimes to the point where the game is unplayable. It seems to be worse if I'm idle for a while and I come back or if I look at a jungle. I don't believe it's to do with my computer as it can run other games, such as Fallout 3 or Borderlands 2, on the highest settings with no lag whatsoever, I've tried playing around with the video settings on Tekkit but they seem to make no difference whatsoever. If anyone can help I'd be very grateful!