Broadcom has been extremely vocal about creating 25- and 50-Gb/s Ethernet standards for the data center. While that work is still in progress at the IEEE, Broadcom is coming out with the Ethernet controller that will help it deliver on those new speeds.
The BCM57300 NetXtreme C-series sits on the network interface card to handle virtual-switch processing for 25- and 50-Gb/s Ethernet, freeing those tasks from the CPU.
That matters because as Ethernet speeds increase, Ethernet processing is chewing up more CPU cycles — up to 33 percent of a high-end Intel processor’s cycles (the Haswell architecture) for a 25-Gb/s connection, says Jim Dworkin, director of product marketing for Broadcom’s controller group.
Back around 2005, that figure was more like 15 percent. And Broadcom’s calculations show it expanding to 45 percent as 50-Gb/s comes around, even if a more advanced Intel chip (the Skylake line) is used.
Ethernet speeds come and go; what’s interesting about 25 and 50 Gb/s is that they’re a step backward from the state-of-the-art 40- and 100-Gb/s connections that were already standardized.
It all comes down to the speed at which signals can be moved around a chip or a board. The high-end standard there has been 10 Gb/s, with multiple lanes of those signals tied together to form a 40- or 100-Gb/s link. Broadcom and others have now upped that serializer/deserializer (serdes) speed to 25 Gb/s.
That means a 50-Gb/s connection is now possible using two lanes, as opposed to four lanes for a 40-Gb/s connection. It’s more economical — so, data center operators are paying attention to 50 Gb/s, even in cases where they’ve already deployed 40 Gb/s, Dworkin says.
Part of what makes the NetXtreme chips useful is that they don’t do all the Ethernet processing in software. They use a hardware-based classification engine called TruFlow. It’s a pipeline of match/action tables that direct Ethernet traffic at the flow level.
Competition in Ethernet controllers includes other big names such as Intel and Mellanox. Broadcom usually claims to have advantages in power consumption and chip size, and the NetXtreme C-series is no exception. The company claims the chips will consume less than 4 W of power, whereas the nearest competing chip consumes 5 W.
The NetXtreme series is sampling now.