I get random lag spikes, and I have no idea why. Obviously the metric ton mods I've installed doesn't help the case, but I can't really figure out the cause of the lag spikes. I've allocated 3GBs of RAM to Minecraft out of my 4, and when check the F3 menu it doesn't seem like the problem is the RAM but what else could it be? I'd imagine if the CPU was the problem it wouldn't be lag spikes, just generally lower fps. I also have fastcraft and optifine installed.