Tag Archives: SFP+ DAC

10GBASE-T vs SFP+ vs SFP+ Cable, Which to Choose for 10GbE Network?

The dramatic growth in data center requires the higher-performance servers, storage and interconnects. From initial 100M, 1G, 10G, to 40G and 100G, high speed Ethernet has never stopped developing. The standard for 10 Gigabit Ethernet (IEEE802.3ae) was ratified in 2002. In 10 Gigabit Ethernet, there are mainly three media: 10G SFP+ transceiver, SFP+ DAC cable and 10GBASE-T SFP transceiver. This post will discuss 10GBASE-T vs SFP+ vs SFP+ cable.

Media Options for 10GbE Network: 10GBASE-T vs SFP+ vs SFP+ Cable

10G SFP+

SFP+ (small form-factor pluggable plus) supports both fibre optic cables and DAC (direct attach cable). It delivers a wide variety of 10GbE Ethernet connectivity options for data center, enterprise wiring closet, and service provider transport applications. But it has the limitations that will prevent the media from moving to every server.

SFP+ Cable

SFP+ cable is designed for 10GbE access layer interconnection in data center. It includes direct attach copper cables and active optical cables. DAC is a lower cost alternative to fibre, but it can support limited transmission distance and it’s not backward-compatible with existing GbE switches. DAC requires the purchase of an adapter card and requires a new top of rack (ToR) switch topology. DAC is more expensive than structured copper channels, and cannot be field terminated.


10GBase-T SFP enables 10GbE connections with unshielded or shielded twisted pair cables over distances up to 100 metres. 10GBase-T technology appears as SPF is not compatible with twisted pair cabling system typically used in data centers. With 10GBase-T SFP, the migration from 1GbE to 10GbE can be easily achieved.

10GBASE-T vs SFP+ vs SFP+ Cable

This part will dicuss 10GBASE-T vs SFP+ vs SFP+ Cable from the aspects of latency and power consumption:


Low latency becomes so important since the adoption of private cloud applications increases. It’s beneficial for ensuring fast response time and reducing CPU (center processing units) idle cycles so that improve data center efficiency.

As to 10GBASE-T SFP, the physical connection (PHY) standard uses block encoding to transport data across the cable without errors. The block encoding requires a block of data to be read into the transmitter PHY, a mathematical function run on the data before the encoded data are sent over the link. It happens the same on the receiver side. This standard specifies 2.6 microseconds for the transmit-receive pair, and the block size requires latency to be less than 2 microseconds. While 10G SFP applies simplified electronics without encoding, and common latency is around 300 nanoseconds per link.

You may think that two microseconds are not high. But what if a TOR infrastructure where traffic is passing 4 hops to reach the destination? 10.4-microsecond delay will be caused when using 10GBASE-T SFP. The following table tells details about the latency of SFP+ cable, 10G SFP and 10GABSE-T SFP for different number of links.

Number of Links SFP+ Cable Latency 10G SFP Latency 10GBASE-T SFP Latency
1 0.3 0.1 2.6
2 0.6 0.2 5.2
3 0.9 0.3 7.8
4 1.2 0.4 10.4
5 1.5 0.5 13.0
6 1.8 0.6 15.6

From the above table, it shows that the latency of 10GBASE-T SFP is the highest. As network links grow, the latency turns to be higher. It’s known that the lower latency, the faster the network speed. High latency in the data center infrastructure results in delays in CPU and application works, therefore limiting data center efficiency and increasing operational costs.

Power Consumption

Power consumption is also one of the important factors to be considered in data centers. Engineers are sensitive to power consumption and find a way to seek the lowest possible power consumption technologies. It’s said that every watt of power consumed, typically two additional watts are needed for cooling.

10GBase-T components today require anywhere from 2 to 5 watts per port at each end of the cable depending on the distance of the cable. But 10G SFP requires about 0.7 watt regardless of distance. The figure below compares the power consumption of three media options of 10GbE Ethernet.

10GBASE-T vs SFP+ vs SFP+ Cable

From this figure, suppose there are 10000 ports in the data center, 10G SFP can greatly save the power. On contrary, 10GBASE-T components consumes the most power. Thus, to save power in the data center, 10G SFP and SFP+ cable should better be selected when deploying thousands of cables in a data center.


From this article, 10G SFP+ and SFP+ cable solutions are better than 10GBASE-T SFP for 10G data center. But 10GbE is not the ultimate goal. Besides factors mentioned in this article, you should also select a cabling solution which can support not only current needs but also future data center deployments when you design 10GbE network. You can find various SFP+ modules and 40G QSFP+ from FS.COM.

Related article: How to Convert SFP+ to 10GBASE-T/RJ45?

FS.COM SFP+ Direct Attach Cable Solution

Meeting the ever growing need to cost-effectively deliver more bandwidth, FS.COM SFP+ Direct Attach Cable delivers lower power, lower latency and higher density for today’s Data Centres and Storage Area Networks.

SFP+ DAC Cables are a low cost alterna-tive to traditional fibre and twisted-pair copper cabling in top-of-rack and middle-of-row Data Center deployments.

In today’s Data Center, more bandwidth is needed to support the use of server virtualization where multiple virtual machines are combined on a single physical host server. To accommodate the ever-growing number of operating systems and applications residing on individual servers, virtualization requires significantly increased data transmission between the servers and switches.

At the same time, the amount and type of devices residing on the network have dramatically increased the amount of data that needs to be transmitted to and from storage area networks (SANs) and Network Attached Storage (NAS). Depending on recent industry forecasts, the amount of enterprise data being transmitted will grow at more than 20% between 2011 and 2016. Consequently, Data Centre managers are looking for cost-effective methods to provide more bandwidth, while optimising power consumption and supporting modularity and scalability.

To meet these requirements, FS.COM has expanded its line of Data CentreSolutions to include SFP+ Direct Attached Cables. A low cost, low power consumption and low latency solution that is ideal for high-density, in-rack 10 gigabit per second (Gb/s) connections between servers and switches, SFP+ Direct Attached Cables feature rugged twinaxial cables that connect directly into a low-profile small form-factor pluggable plus (SFP+) diecast connector housing.

FS.COM SFP+ Direct Attached Cables offer the smallest 10 gigabit form factor and a small overall cable diametre for higher density and optimised rack space in 10 gigabit Ethernet (GbE) uplinks and 10 gigabit Fibre Channel SAN and NAS input/output connections. The use of SFP+ Direct Attached Cables can cost up to three times less than fibre optic solutions, while offering lower latency and consuming up to 50% less power per port than current copper twisted-pair cabling systems.

Becoming increasingly popular for short distance top-of-rack (ToR) and middle-of-row (MoR) Data Centre deployments, and expected to account for over 40% of 10 gigabit equipment ports, SFP+ Direct Attached Cables also provide enhanced scalability and flexibility. By connecting several servers or storage devices together in a single rack, the use of intermediate patch panels is eliminated and cabling outside of the rack is limited to the main switch connection, making it easy to move racks, deploy one rack at a time and isolate cabling changes to a single rack.

SFP+ Direct Attached Cables provide better cable management for high-density deployments and enhanced electrical characteristics for the most reliable signal transmission.

  • Supports 10 Gb/s data rates with backwards compatibility to 1 Gb/s
  • Supports 8x/4x/2x/1x Fibre Channel data rates for SANs and NAS
  • Compliant with the latest SFF-8431 specifications
  • Passive assemblies available in 1-foot increments from 1.6 to 32.8 ft (0.5 to 10 m)
  • Active assemblies available in 2-foot increments from 3.3 to 39.4 ft (1 to 12 m)
  • Connector cage designed for high-speed differential signaling
  • Easy pull-to-release latching mechanism
  • Extremely short lead times on all passive assemblies
  • Backed by superior support and a 10-year product warranty

FS.COM Compatible Interconnect Solutions: the 10-Gigabit and 40-Gigabit High Speed Cable Compatible for Cisco. FS.COM offers SFP+ twinax copper cables, SFP+ active optical cables, QSFP copper cable, breakout cable and QSFP AOC cables with 100% compatibility for Cisco.

Ordering Information

SFP+ Passive Cable Assembly, Cisco Compatible, 10G:

  • Cisco SFP-H10GB-CU1M, 1 metre, 30AWG, $18.00
  • Cisco SFP-H10GB-CU2M, 2 metre, 30AWG, $22.00
  • Cisco SFP-H10GB-CU3M, 3 metre, 30AWG, $27.00
  • Cisco SFP-H10GB-CU5M, 5 metre, 24AWG, $38.00
  • Cisco SFP-H10GB-CU7M, 7 metre, 24AWG, $75.00
  • Cisco SFP-H10GB-CU10M, 10 metre, 28AWG, $88.00

Cisco SFP-H10GB-CU5M SFP+ direct attach cable

Cisco SFP-H10GB-CU5M SFP+ cable

SFP+ Active Cable Assembly, Cisco Compatible, 10G:

  • Cisco SFP-10G-AOC1M, 1 metre, $70.00
  • Cisco SFP-10G-AOC2M, 2 metre, $71.00
  • Cisco SFP-10G-AOC3M, 3 metre, $72.00
  • Cisco SFP-10G-AOC5M, 5 metre, $74.00
  • Cisco SFP-10G-AOC7M, 7 metre, $76.00
  • Cisco SFP-10G-AOC10M, 10 metre, $79.00

Cisco SFP-10G-AOC1M cable

Cisco SFP-10G-AOC1M cable

QSFP+ Active Cable Assembly, Cisco Compatible, 10G:

  • Cisco QSFP-4X10G-AOC1M, 1 metre, $281.00
  • Cisco QSFP-4X10G-AOC2M, 2 metre, $287.00
  • Cisco QSFP-4X10G-AOC3M, 3 metre, $292.00
  • Cisco QSFP-4X10G-AOC5M, 5 metre, $302.00
  • Cisco QSFP-4X10G-AOC7M, 7 metre, $313.00
  • Cisco QSFP-4X10G-AOC10M, 10 metre, $333.00

Cisco QSFP-4X10G-AOC2M Compatible 40GBASE QSFP to 4 SFP+ Active cable

Cisco QSFP-4X10G-AOC2M Compatible 40GBASE QSFP to 4 SFP+ Active cable

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