I am running OPNsense 18.1.10-i386 on a Intel(R) Celeron(R) CPU N3150 @ 1.60GHz (4 cores) with 16GB RAM and 120GB SSD.
why do you install the i386 (32Bit) OPNsense on a 64-Bit CPU?
And AFAIK the Intel Celeron N3150 supports a max. memory size of 8GB RAM