I’ve written before about how Cisco Silicon One changes the paradigm of energy consumption and why that matters to the environment and how we’re dramatically more efficient than other 12.8T silicon. As the father of two young children, this is something I spend a considerable amount of my free time fretting over. As an engineer at Cisco, I feel fortunate that I can help control the continued rise of carbon emissions by developing products that focus on power efficiency.

Working for an equipment manufacturer makes it easy to focus on how the advancements we’ve made with Cisco Silicon One significantly affect one box but miss the larger impacts of what happens at a full web scale data center level. So I spent some time analyzing how building systems with Cisco Silicon One could impact customers deploying massive web scale networks. I created a model for a web scale data center with 110,000 servers to help you understand the ramifications.

Going into the analysis, I wasn’t really sure what to expect, but I was amazed when I found that simply by deploying Cisco Silicon One customers could save up to 580kW and up to $9.75 million dollars. Let’s look closer at what I modeled and what I found.

Most web scale customers treat data center topologies as carefully guarded secrets so I created a representative topology using 1RU pizza boxes with a 3.2Tbps Top of Rack (TOR) switch, a 12.8Tbps leaf switch, a 12.8Tbps spine switch, and a 12.8Tbps Data Center Interconnect (DCI) router.

I then analyzed how energy consumed by the switch silicon is delivered through a system and the greater facility, as well as how the heat generated in the process is removed. The less efficient the systems and facilities are, the larger the savings would be with Cisco Silicon One.

As an engineer, I find it more persuasive to lean conservative in my estimates and show potential savings even with highly efficient systems and facilities. The model makes the following assumptions: a total system efficiency of 85 percent and a facility Power Usage Efficiency (PUE) of 1.2.

Both are close to industry-leading numbers. Together these show that for every watt consumed by the switch silicon, 1.41W will be consumed by the facility.

Because of the impressive efficiency of Cisco Silicon One versus other silicon on the market, simply by building a network with Cisco Silicon One could save customers up to 580kW or 30 percent of network switching power.

As impressive as the power savings is, what’s more interesting is what saving that much power means to the customer.

According to the U.S. Energy Information Administration (EIA), the average commercial price per kilowatt-hour (kWh) is 10.67 cents, while in low-cost regions it can be as low as 4.68 cents per kWh. And according to Turner & Townsend, building a 30MW web scale data center costs between $7.1 and $8 per watt in the United States. Together, these may enable a customer to save between $6.8 million and $9.75 million over a 10-year period.

The power reduction in networking can also be used to add more revenue-generating servers. With an average server power of 500W, this translates to being able to add another 966 servers or roughly a one percent increase in the total server count of the facility.

These were astounding findings. But what’s most impressive about Cisco Silicon One is that while we can be so energy efficient, we also provide the highest performance and most flexible routing and web scale switching silicon on the market under a fully unified architecture.

You can read more about the analysis in my white paper, Cisco Silicon One Web Scale Data Center Study.


Rakesh Chopra

Cisco SVP & Fellow

Common Hardware Group Architecture and Platforming