Bogdan-G: There's still the Mystcraft profiling running with fairly severe slowdown by garbage collection or all cpu cores being busy, so the results aren't conclusive. The sampler report file is corrupted so I can't read it. I've uploaded a new Sampler version with various fixes.
file broken? hm.. while writing the file to disk game fell. Ok, im update in local mopdpack sampler mod and del Mystcraft.
YAY, MC no crash O_o
But fps in distance 8 periods(range 10-80 sec, on 2-3 min) drop to 1-8; outside the periods 20-80fps, if distance 3 - fps stable 80-120(no drops); down tps in server found to 1(periods), ticks in bar F3 less, but still not enough. Reports normal write in disk, thanks for update sampler! Game still peaceful gamemode. Process game ~3.6gb (Last launch from mystcraft same 3.6gb) and 2500m heap(use from 800m to 2300m last run). In after start world, audio not play(sounds and effects) ~30 min.