I have same issue, drops from 30+ fps to 1 and then freezes
Intel® Core™ i3-3120M CPU @ 2.50GHz x4
geforce GT 740m (2gb) driver version: 332.21
4gb RAM
windows 8.1 64 bit
launch options: -nosplash -skipIntro -world=empty -high -nopause -maxMem=4097 -maxVRAM=2047 -cpuCount=2 -exThreads=4
also, my cpu and gpu temperatures don't go over 61°C

well, i died, waited 20 minutes, reconnected and i was alive with all my gear at the same spot...

happened to me too...