Hi, im using HiveOS long time, but now i spotted that in the web control panel of miner the FREE RAM is only ~100mb from 4GB. and some times its being normal about 2gb is free. rig sometimes crashing, whats the problem? 
please provide more info
algo
cards
specs
pool
screenshots
the more info u provide, the better help u get
beside that , i would like to suggest if u are having any issue no matter what level, try changing the following
1- OC settings
2- algo
3- pool
if nothing of these works
re-flash hiveOS ( which is a 10 min job) instead of wasting hours trouble shooting