10GBASE-T to Obsolete SFP+ Direct Attach?

by Lisa Huff

If history repeats itself, like it often does in Ethernet networking, the maturing of 10GBASE-T technology will allow equipment manufacturers to get to a more cost-effective solution than the current optical one. This will accelerate the adoption rate of 10GigE in the data center for both Top-of-Rack (ToR) and End-of-Row (EoR) configurations. But will 10GBASE-T supplant SFP+ Direct Attach in the data center? Good question and one that I believe we’re on the brink of getting an answer to.


I’ve noted in previous posts that the main reason 10GBASE-T hasn’t been adopted in switches sooner was because of the chips high power consumption (more than 5W). But with the advent of 40-nm processing and innovative quad-port circuit design, chip makers like Aquantia, Broadcom (BRCM), Chelsio, SolarFlare and Tehuti are all touting devices that consume less than 3W. This enables the medium-port-density that switch manufacturers need for their first blades with 10GBASE-T. And indeed, these implementations are starting to appear.


Blade Networks, Brocade Communications (BRCD), Cisco (CSCO), and Extreme Networks (EXTR) all have various products with 10GBASE-T ports. But all of these OEMs say that while 10GBASE-T may be more cost-effective on the surface, end users may still choose the SFP+ direct attach for the flexibility it allows them in their networks. The whole idea of the pluggable modules – you can use copper, short-reach optics or long-reach optics. So if you need to make a lot of moves, adds and changes, you don’t have to buy new equipment, just switch modules or cable assemblies. This is important in the data center environment. I believe 10GBASE-T will make a dent in SFP+ Direct Attach shipments, but they will coexist, just like their predecessors for Gigabit Ethernet (SFP and 1000BASE-T) are doing right now.


More of a question for me is, how will finally having 10GBASE-T influence the 10GBASE-SR market?