The TS-664 is a compact 6-bay NAS with superior performance. Supporting up to 120TB of storage and 4TB of M.2 SSD caching* at an affordable price, the TS-664 meets your multitasking challenges for file management, backup, collaboration, and video conversion. The TS-664 uses the QTS operating system by default. You can also choose the QuTS hero operating system. QuTS hero offers benefits such as ZFS data integrity and WORM technology to prevent data manipulation. (The switch to QuTS hero is supported starting from QTS 5.2.1.) Use six 3.5-inch 24TB hard drives in RAID 5 and two 2TB M.2 SSDs. Hard drives and SSDs are sold separately. intel-celeron-20212.5GbEhdhdmi The 2.5GbE is a must! The TS-664 is as fast as a single-port 10GbE NAS with transfer speeds of up to 589MB/s by configuring link aggregation with the two built-in 2.5GbE ports (2.5G/1G/100M). Quad-core for multitasking Handle additional tasks, stream more multimedia content, and run more services with an Intel® quad-core processor optimized for multitasking. Smooth video conversion Integrated graphics card for enhanced video conversion, allowing smooth video streaming from the NAS to mobile devices. Upgrade to dual-port 10GbE Future-proof your network connection by installing a dual-port 10GbE PCIe network card that offers transfer speeds of up to 1,644MB/s. Faster USB transfer Two USB 3.2 Gen 2 (10 Gbit/s) ports allow for faster backups to/from USB devices. More M.2 NVMe SSDs If two M.2 slots are not enough, install a QM2 PCIe expansion card for additional M.2 SSD slots.