Terminator 5 Adapter Range

High Performance, Dual Port 10GbE Unified Wire Adapter

Enables TCP, UDP, ISCSI, iWARP and FCoE Offload over Single Unified Wire with SR-IOV, EVB/VNTag, DCB


Chelsio’s T520-CR is a dual port 10 Gigabit Ethernet Unified Wire adapter with PCI Express 3 host bus interface, optimized for cloud computing, HPC, virtualization, storage, and other data center applications.

The fifth-generation (T5) technology from Chelsio provides the highest 10GbE performance available and dramatically lowers host-system CPU communications overhead with on-board hardware that off-loads TCP/IP, iSCSI, FCoE and iWARP RDMA processing from its host system. T520-CR frees up host CPU cycles for useful applications. The system achieves increased bandwidth, lower latency, and uses less power.


The Unified Wire Solution

With the T520-CR, Chelsio is enabling a unified wire for LAN, SAN, and cluster traffic. This unified wire was made possible by the high bandwidth and low latency of 10GbE combined with storage and cluster protocols operating over TCP/IP (iSCSI, FCoE, and iWARP respectively). In parallel, operating systems and hypervisors have incorporated native support for iSCSI and database applications are now supporting file-based storage protocols such as NFS as an alternative to SANs.

T520-CR includes a full-fledged integrated Traffic Manager for robust flow control, traffic management, and QoS.

Fibre Channel over Ethernet (FCoE) provides a transition path from legacy SANs to converged networks. Expanding its unified wire approach, Chelsio has added FCoE hardware support for the adapter.

The adapter’s two ports and IEEE 802.3ad link aggregation/failover features are ideal for critical network applications that require redundancy and high-availability capabilities.

T520-CR Ethernet-only networking reduces the data center’s cost in network adapters, cables, switches, rack space, power, equipment spares, management tools, planning, networking skills and installation.


T5 – Fifth-Generation Protocol Offload Engine

The T5 is Chelsio’s fifth-generation TCP offload (TOE) design, fourth-generation iSCSI design, and third-generation iWARP (RDMA) implementation. For the server connection, the T5 chip included a PCI Express v3.0 x8 host bus interface. With support for the 8 Gbps Gen 3 data rate, the PCIe interface provides up to 64 Gbps for bandwidth to the server. T5 also provides support for PCIe I/O virtualization. Most of the T5 features are carried over from those found on T4.



The T5 has hundreds of programmable registers for protocol configurations, RFCs, and offload control. The T520-CR can offload processing per connection, per-server, per-interface, and globally and simultaneously tunnel traffic from non-offloaded connections to the host processor for the native TCP/IP stack to process. The T520-CR provides a flexible zero-copy capability for regular TCP connections, requiring no changes to the sender, to deliver line rate performance at minimal CPU utilization.


Packet Switching and Routing

T520-CR integrates a high performance packet switch, which allows switching traffic from any of the input ports to any of the output ports (wire-to-wire) and from any of the output ports to any of the input ports (host-to-host).


Robust, Proven Solution

Subjected to thousands of hours of compatibility testing, over multiple years of stress testing by several OEM test suites and production deployment in servers, storage systems, and cluster computing, Chelsio’s robust, stable protocol offload technology delivers proven performance in a wide range of environments. The T520-CR is generations ahead of competing products.



Chelsio offers a full suite of protocol software drivers with the T520-CR adapters. See Support Page for the latest information. The software supports operation in both protocol-offload and non-offload modes.


Ordering Information

Model: T520-CR
Physical Interface: 10GBASE-SR or LR*
Connector: LC Duplex
Media: MMF or SMF.

*SFP+ optics sold separately. Only Chelsio-supplied modules may be used.



SM10G-SR:10G short-reach SFP+ optic module
TAPCABLE1M:Twinax passive cable,1M
SM10G-LR:10G long-reach SFP+ optic module
TAPCABLE3M:Twinax passive cable, 3M
SRCABLE3M:Fibre optic cable, 10GBASE-SR, 3M
TAPCABLE5M:Twinax passive cable,5M
LRCABLE3M:Fibre optic cable, 10GBASE-LR, 3M