The advent of 10 Gigabit Ethernet (10 GigE) into the datacenter will bring with it a new standard for an Ethernet-based lossless fabric. It is variously known as Converged Enhanced Ethernet (CEE), Data Center Ethernet (DCE) and Data Center Bridging (DCB), but they are all essentially the same thing. The important aspect of this technology is that it will enable storage and compute boxes to share a common standard fabric — in this case, Ethernet.
The prospect of lossless datacenter Ethernet at 10 gigabits/second speeds is giving InfiniBand vendors something to think about since up until now they had the market cornered in high-performance interconnects that spanned both compute and storage nodes. The good news for them is that InfiniBand’s market, which is still mostly HPC, won’t be threatened by the arrival of lossless Ethernet.
From a performance standpoint, 10 GigE is still InfiniBand-lite. QDR InfiniBand delivers 40 gigabits per second (Gbps) — although overhead reduces the net bandwidth somewhat — and 80 Gbps is already on the drawing board. More importantly, InfiniBand still beats Ethernet handily in the latency department. And for price-performance, InfiniBand is the clear winner over any other network fabric, including 10 GigE.
But in the larger datacenter market, Ethernet still offers the best plug and play experience, not to mention backward compatibility with legacy apps. As cloud computing starts to take hold over the next few years, 10 GigE is destined to be the interconnect of choice. And for HPC setups that don’t require the ultimate in performance, 10 GigE is likely to replace the current Gigabit Ethernet used for such systems.
Over the past couple of years, Mellanox Technologies has made several forays into the Ethernet landscape. The company has been busy developing and deploying a set of converged Ethernet products around its virtual protocol interconnect technology and ConnectX and BridgeX architectures.
Not wanting to miss out on the fun, last week Voltaire announced its own Ethernet strategy, which will initially be based on a new line of 10 GigE core switches intended for datacenter consolidation, virtualization and cloud computing. The new offerings will enable the company to go after a much larger slice of the datacenter network pie. Ethernet represents a market of around $2 billion versus just hundreds of millions for InfiniBand.
Details about the new Voltaire switches will be under wraps until this summer, with general availability scheduled for the end of the year. By that time, the company is hoping the 10 GigE ecosystem and the economy will have solidified enough to create demand for the core switches that Voltaire has in mind. “We believe the timing of our Ethernet product is exactly right given the refresh cycle in today’s datacenters,” said Voltaire CEO Ronnie Kenneth during the Q1 earnings call last week.
The company’s overall approach is to deliver Ethernet switching with many of the same capabilities as its InfiniBand offerings, namely lossless data, low latency, multi-pathing, an open standard RDMA-based software stack, I/O virtualization, cut-through switching, and congestion management. This is no coincidence; datacenter Ethernet specifies a fabric that resembles InfiniBand much more than it does traditional Ethernet.
Voltaire’s new Unified Fabric Manager (UFM) software, which was deployed on a 700-node supercomputer at the High Performance Computing Center Stuttgart, was built for InfiniBand, but the underlying technology applies to any shared network fabric. UFM is just one component of Voltaire’s InfiniBand portfolio it can tap into as it builds it Ethernet business.
Although the specs on the upcoming switches are still secret, Voltaire is claiming that its 10 GigE gear will deliver up to 10 times lower latency, 4 times the core capacity, and consume 3 times less power than a comparable Cisco solution on a 1,000-node server setup. Not only that, Voltaire says it can do it all for about half the cost.
According to Voltaire Vice President of Marketing Asaf Somekh, since their implementation is centered on layer 2 switches, they can avoid the costs associated with the more expensive layer 3-7 services that other vendors have added in their core datacenter switches. Voltaire also intends to mimic the relatively flat architecture that is prevalent in InfiniBand switching. This contrasts with the multi-tier approach common with more typical Ethernet environments. “You can build a very large datacenter with thousands of nodes with only two tiers of switches,” explains Somekh, “while with Cisco solutions, you need three, sometimes four tiers to build something of similar size.” The advantage of a flatter architecture is not only reduced costs, but also lower latency since there are less hops in the data path.
Voltaire’s Ethernet switch effort has been going on for the past 18 months, but it’s likely that Cisco’s recent push into the server business prompted Voltaire to start talking about the upcoming switches several months in advance of their official launch. From Somekh’s perspective, Cisco’s recent entry into the server business places them at odds with former OEM partners like IBM and HP. “Cisco actually did a nice favor for us by alienating the server companies with historical partnerships with Cisco,” he said.
Because of Voltaire’s InfiniBand business, the company already has relationships with many of the same server vendors that are likely to be looking for Ethernet switch partners with less conflicted agendas than Cisco. Currently Voltaire’s biggest OEM partners include IBM, HP, NEC, Bull, Sun (soon to be Oracle) and Rackable/SGI, and Somekh estimates that 75 to 80 percent of their InfiniBand revenue is captured via these relationships. Somekh says they are already working with some OEMs on specific customer proposals using 10 GigE setups.
As the 10 GigE switching space heats up, Voltaire will be going up against Cisco, Brocade, Juniper Networks, Force10 and a number of smaller players, like Woven Systems. If all goes according to schedule, Voltaire will deliver one of the first converged Ethernet switch solutions to the market, but longer term the company is counting on its InfiniBand-like approach, experience in lossless fabric management, and established OEM relationships to distinguish itself from the growing crowd of 10 GigE vendors.