2GB DDR3L-1866 memory (expandable up to 6GB) / Dual-core processor with AES-NI hardware encryption engine. Dual Core 2.0 burst up to 2.5 GHz / Encrypted sequential throughput performance at over 113 MB/s reading and 112 MB/s writing / Advanced Btrfs file system offering 65,000 system-wide snapshots and 1,024 snapshots per shared folder / Live transcoding of up to two concurrent H.265/H.264 4K video streaming

4GB DDR3L-1866 memory, expandable up to 8GB; Scalable up to 9 drives with Synology DX517 / Quad-core processor with AES-NI hardware encryption engine; Dual 1GbE LAN with failover and Link Aggregation support / Encrypted sequential throughput at over 225 MB/s reading and 221 MB/s writing / Advanced file system offering 65,000 system-wide snapshots and 1,024 snapshots per shared folder / Dual-channel H.265/H.264 4K video transcoding on the fly. Operating temperature: 5°C to 40°C (40°F to 104°F)