The Platform’s Timothy Prickett Morgan reports that Google is eyeing networking throughput capabilities of 5 petabits per second. However, as Google Fellow Amin Vahdat recently pointed out, the industry currently “underprovisions” networks because it doesn’t (yet) know how to build big networks capable of delivering “lots” of bandwidth.
According to Vahdat, the ideal network should have 1 Mbit/sec of I/O for every 1 MHz of computation to maintain a balanced system in a parallel computing environment.
“[He] pointed out that with the adoption of flash today and other non-volatile memories in the future, which have very high bandwidth and very low latency requirements, keeping the network in balance with compute and storage is going to be a big challenge,” writes Morgan.
Image Credit: The Platform (via Google)
To illustrate his point, Vahdat discussed a hypothetical data center (see image above) populated by 32-core processor servers running at 2.5 GHz. The servers are equipped with 100 Gb/sec ports that reach out into the datacenter network.
Commenting on the above report, Mohit Gupta, a director of product marketing at Rambus, says there is a definite need to move from a 10Gbps serial link data rate to 25Gbps or 50Gbps and perhaps even higher as bandwidth and capacity requirements continue to increase.
“Moving to higher data rate links in data centers and servers improves overall efficiency. For example, a 100GbE implemented in 10x10Gbps configuration significantly bolsters overhead, especially in comparison to 4x25Gbps systems,” he explained. “Of course, higher data rate serial links are more complex and challenging to design. Remember, systems needs to run higher speeds (2.5x) for the same cables, traces and backplanes – all while supporting backwards compatibility for legacy standards running at 1.25Gbps.”
Gupta also noted that the power-performance ratio is another important variable to keep in mind when it comes to increasing data rates.
“Perhaps the biggest cost involved in running a data center is electricity consumption,” he added. “As such, there is a considerable amount of emphasis on keeping the power low for such links – even though they are targeted for higher speeds. This poses additional challenges for both system and serial link designers.”