Synology DS1821+ QC2,2GhzCPU/4GbDDR4(upto32)/RAID0,1,10,5,6/upto 8hot plug HDD SATA(3,5′ or 2,5′)(upto18 with 2xDX517)+ 2 M2 slots/ 4xUSB3.2/2eSATA/4GigE(+1Expslot)/iSCSI/2xIPcam(upto40)