Hi there Yulife ! I've been following the thread ever since the release and I have enjoyed many hours of fun along with my brother on your modpack, so thanks a lot for all this
As some people pointed out in the last few pages, there definitely is something weird going with NEI. I get lag spikes of hell when I use it, but it seems a bit random : it seems that the recipe function is a lot lighter in terms of performance impact than the "Usage" function. The latter makes my PC kneel down for a few seconds, to the point it sometimes even crashes. This takes the form of a tremendous CPU usage (70%+), and I think it's the only time I've seen my CPU under such load : it's an i7-4790K overclocked at 4.8 GHz, so 70% usage is a huuuuuuge amount of power required for NEI.
It's not that important, but I would appreciate if you could investigate this issue and see if there's anything to do to make NEI work as it did in 1.6.4 or even in other modpacks. I'm ready to help you in any way I can by providing you logs or perf graphs, feel free to ask for them.