Hello all,
Thanks God, we've got more powerful than what I have now Dell PowerEdge R720 with 256GB of RAM, 8 SSDs and 48 cores (2 CPUs * 12 cores each * 2 virtual) with 10Gbs NICs :)
Created RAID-10, tuned XFS, created LACP with two NICs, also tuned together with switch, so got 18-19Gbs...