Dell Unity XT 680XT
The Dell Unity XT 680 is a high-performance hybrid flash storage array engineered for enterprise data centers consolidating massive transactional workloads, large-scale virtualization, and multi-tenant file services. Powered by dual active-active controllers with 384GB of system memory and 24 Intel Xeon processing cores, it scales up to 1000 drives and 8.0PB of raw capacity. With FAST VP automated tiering and FAST Cache SSD read acceleration, the 680XT maximizes performance while controlling spinning-disk storage economics. Pre-owned system purchasers should inspect lithium-ion cache protection batteries and verify all I/O module configurations.
Also written as: Unity XT 680, Dell EMC Unity XT 680, Unity 680XT Hybrid
Specifications
| Brand | Dell |
|---|---|
| Family | Unity XT |
| Form factor | 2U rack |
| Released | May 2019 |
| Cpu platform | Dual active-active storage processors (SPs), Intel Xeon Skylake 12-core (1.9 GHz) per SP |
| Memory max (GB) | 384 |
| Drive bays | Up to 25x 2.5-inch drives in base DPE; expands up to 1000 drives across SAS DAEs |
| Raw capacity | Up to 8.0 PB raw capacity |
| Network onboard | 4-port 10GbE / 1GbE embedded; 2x I/O module slots per SP supporting 16Gb/32Gb FC or 25GbE optical |
| Power supply | Dual redundant hot-plug 1800W Platinum power supplies |
Generations
- Previous generation: Dell Unity 500
- Next generation: Dell PowerStore 3000T
Works together
How the Dell Unity XT 680XT connects to servers, storage and the network: 3 ways, with the parts and products on each path.
Fibre Channel SAN
Match the speed: 16Gb and 32Gb FC HBAs, switches and array ports work together, and each generation also runs one or two speeds below its own (a 32Gb port runs at 16Gb and 8Gb).
Servers
Dell PowerEdge R650 1U rack
Dell PowerEdge R750 2U rack
Dell PowerEdge R640 1U rack
Dell PowerEdge R740 2U rack
Dell PowerEdge R660 1U rack
Dell PowerEdge R760 2U rack
Adapters for the server
540-BBUU Dell Emulex LPe31002 Dual Port 16Gb Fibre Channel Host Bus Adapter
540-BBUV Dell QLogic 2692 Dual Port 16Gb Fibre Channel Host Bus Adapter
540-BCMT Dell QLogic 2772 Dual Port 32Gb Fibre Channel PCIe Adapter
540-BCMU Dell Emulex LPe35002 Dual Port 32Gb Fibre Channel PCIe Adapter
Switches
Dell Connectrix DS-6610B 1U rack
Dell Connectrix DS-6620B 1U rack
Dell Connectrix MDS-9148T 1U rack
Dell Connectrix DS-7720B 1U rack
Optics
iSCSI and NVMe/TCP over Ethernet
Keep the speed the same at all three points: a 25GbE server, a 25GbE switch port and a 25GbE array port. Mixed speeds work but the slowest link sets the pace.
Servers
- Dell PowerEdge R650 1U rack
- Dell PowerEdge R750 2U rack
- Dell PowerEdge R640 1U rack
- Dell PowerEdge R740 2U rack
- Dell PowerEdge R660 1U rack
- Dell PowerEdge R760 2U rack
Adapters for the server
540-BBGO Dell Broadcom 57416 Dual Port 10GBASE-T RJ45 PCIe Adapter
540-BBGY Dell Broadcom 57414 Dual Port 10/25GbE SFP28 PCIe Low Profile Network Adapter
540-BBHB Dell Broadcom 57414 Dual Port 10/25GbE SFP28 OCP 3.0 Mezzanine Network Adapter
540-BBRL Dell Intel X710 Quad Port 10GbE SFP+ Full-Height PCIe Adapter
Switches
Dell PowerSwitch S5248F-ON 1U rack
Dell PowerSwitch S4148F-ON 1U rack
Dell PowerSwitch S5212F-ON 1U rack
Dell PowerSwitch S5224F-ON 1U rack
Optics
407-BBOU Dell 10GbE SFP+ SR Optical Transceiver (850nm, 300m MMF)
407-BCBF Dell 25GbE SFP28 SR Optical Transceiver (850nm, 100m MMF)
SFP-10G-SR-AR Arista 10GBASE-SR SFP+ Optical Transceiver
File storage (NFS and SMB)
Front-end ports face the clients; back-end ports (on scale-out systems) connect the nodes to each other and need their own switch pair.
Servers
- Dell PowerEdge R650 1U rack
- Dell PowerEdge R750 2U rack
- Dell PowerEdge R640 1U rack
- Dell PowerEdge R740 2U rack
- Dell PowerEdge R660 1U rack
- Dell PowerEdge R760 2U rack
Adapters for the server
- 540-BBGO Dell Broadcom 57416 Dual Port 10GBASE-T RJ45 PCIe Adapter
- 540-BBGY Dell Broadcom 57414 Dual Port 10/25GbE SFP28 PCIe Low Profile Network Adapter
- 540-BBHB Dell Broadcom 57414 Dual Port 10/25GbE SFP28 OCP 3.0 Mezzanine Network Adapter
- 540-BBRL Dell Intel X710 Quad Port 10GbE SFP+ Full-Height PCIe Adapter
Switches
- Dell PowerSwitch S5248F-ON 1U rack
- Dell PowerSwitch S4148F-ON 1U rack
- Dell PowerSwitch S5212F-ON 1U rack
- Dell PowerSwitch S5224F-ON 1U rack
Optics
- 407-BBOU Dell 10GbE SFP+ SR Optical Transceiver (850nm, 300m MMF)
- 407-BCBF Dell 25GbE SFP28 SR Optical Transceiver (850nm, 100m MMF)
- SFP-10G-SR-AR Arista 10GBASE-SR SFP+ Optical Transceiver
Plan and size it
- Draw this setup in the topology planner mrplanb.com
- Add up rack power and space rack-density.com
- Virtualization storage Ledger: scored storage platforms mrplanb.com
- SAN transport and NVMe over FC for backup mrplanb.com
- Dell E-Lab Navigator (Dell interoperability) dell.com
Check compatibility with Dell
Before you buy, confirm the exact configuration against the vendor's own lists: firmware levels, operating systems, adapters and optics that Dell has tested with the Dell Unity XT 680XT.
- Compatibility Dell E-Lab Navigator (storage and SAN interoperability) (free vendor sign-in)
- Support Dell Support: drivers, manuals and service tag lookup
Equivalent models from other brands
- NetApp FAS8700
- HPE Alletra 9000 · compare
Buying a used 680XT: what to check
Verify memory allocation (192GB per SP, 384GB total), check BBU battery module status, confirm 16Gb/32Gb FC transceivers, and test multi-DAE SAS expansion connectivity.
FAQ
What is the memory footprint on the Unity XT 680?
384GB total system RAM across dual Storage Processors (192GB per SP).
How many hard drives can the 680XT address?
Up to 1000 drives supporting up to 8.0 PB of raw storage capacity.
Buying or selling 680XT?
New, refurbished or used. Tell us the quantity and condition and we connect you with a vetted reseller in your region, usually within one working day.
Sources
- Dell Unity XT 680 Spec Sheet, checked 2026-10-27