RoCE: An Ethernet-InfiniBand Love Story

By Michael Feldman

April 22, 2010

To go along with the low-latency theme of this week’s High Performance Computing Linux Financial Markets confab in New York City, the InfiniBand Trade Association (IBTA) announced the release of the RDMA over Converged Ethernet standard that brings InfiniBand-like performance and efficiency into the Ethernet realm.

Abbreviated RoCE (and pronounced “Rocky”), the new standard allows the RDMA guts of InfiniBand to run over Ethernet. Basically the IBTA has taken the InfiniBand stack, left the IB transport and network layers intact, and swapped the IB link layer for Ethernet. Or as OpenFabrics Alliance Executive Director Bill Boas put it: “The only change here is that the verbs in the InfiniBand standard have been implemented over Ethernet.”

This is a much simpler solution than iWARP (Internet Wide Area RDMA Protocol), which also uses RDMA, but incorporates TCP/IP into the stack. In a sense, iWARP tried to unify InfiniBand and IP, but that model has garnered limited appeal. Supporting the TCP/IP stack meant latency could only get into the 10 microsecond range. Freed of that extra processing burden, RoCE latency can approach 1-3 microsecond territory. And it can be implemented more cheaply and with less power consumption. Yes, IP support is missing, but in a closed cluster environment, you would normally just use a gateway node to talk to the outside world.

In general, RoCE is aimed at users of clustered computing setups who might otherwise have opted for InfiniBand because of its speed and agility, but who are already married to Ethernet — either to maintain compatibility with existing storage networks and compute infrastructure or because their local datacenter already has a big investment in Ethernet technology, expertise and management tools. Mellanox has been talking about this technology for a year or so, under the moniker low-latency Ethernet.

“Essentially what you’re able to do now is run close to InfiniBand-like latency over 10 Gigabit Ethernet,” says Brian Sparks, IBTA marketing working group co-chair and director of marketing communications at Mellanox . “But you don’t have the InfiniBand barrier and the learning curve that goes with that.”

RoCE isn’t quite InfiniBand-strength, though. QDR IB nets 32 Gbps and sub-microsecond latencies, while RoCE is currently limited to 10 Gig and latencies closer to single-digit microseconds. For most apps, though, 10 Gig is plenty of bandwidth (and there’s a clean path to 40 and 100 Gig when Ethernet catches up). The real hurt is on the latency side.

Financial services, database warehousing, cloud computing and related virtualization apps are all potential targets of this technology. One of the tastiest low-hanging fruits for RoCE is high frequency trading (HFT), an Ethernet-based application that is all about latency. HFT is a highly lucrative class of algorithmic trading that relies far more on network performance than compute muscle. The object of the game is to turn reams of market data coming in from Ethernet-based ticker feeds into split-second arbitrage opportunities. One person I recently spoke with characterized it as “picking up a nickel in front of a freight train.” RoCE seems tailor-made for this type of application.

In more traditional HPC, RoCE could have plenty of takers. Again, the real draw here is the ubiquity of the Ethernet ecosystem and the promise of near-InfiniBand performance. It’s worth noting that more than half the systems on the TOP500 list are still employing Ethernet interconnects. That’s because there are plenty of big cluster-based workloads (for example, data mining) that don’t require obsessively tight coupling, but would still benefit from better latency than vanilla Ethernet. As HPC makes deeper inroads into the enterprise, RoCE could look fill this role.

As of this week, RoCE is implemented in OpenFabrics Enterprise Distribution (OFED) 1.5.1. The Linux version is available today, with a Windows implementation to follow later this year. That makes it especially nice for applications already written for OFED RDMA. In these cases, there would be no need to twiddle with the code again; the apps should just auto-magically run over any RoCE fabric.

On the hardware side, basically you need an L2 Ethernet switch with IEEE DCB (Data Center Bridging, aka Converged Enhanced Ethernet) with support for priority flow control. On the compute or storage server end, you need an RoCE-capable network adapter. Expect the most enthusiastic vendors to come out with products later this year. Mellanox has already declared its intentions to offer RoCE-friendly adapters. OpenFabrics will release a software-based RoCE later in the second quarter. Soft-RoCE will make a regular 10GbE NIC act like the hardware version.

One might wonder why the IBTA and its InfiniBand-loving members decided to push an Ethernet protocol at all. If RoCE is successful, there’s bound to be some cannibalization of the InfiniBand market. But that’s the wrong way to think about it. First, there are no InfiniBand vendors anymore, at least not in the strict sense. All these companies — Mellanox, Voltaire and QLogic — offer Ethernet products of one sort or another. The market decided some time ago that IB technology would only spread so far. RoCE is another way for these vendors to reach customers they couldn’t attract before. The calculation is that there’s enough daylight between RoCE and InfiniBand to support the viability of both technologies.

Subscribe to HPCwire's Weekly Update!

Be the most informed person in the room! Stay ahead of the tech trends with industry updates delivered to you every week!

ISC 2024 Takeaways: Love for Top500, Extending HPC Systems, and Media Bashing

May 23, 2024

The ISC High Performance show is typically about time-to-science, but breakout sessions also focused on Europe's tech sovereignty, server infrastructure, storage, throughput, and new computing technologies. This round Read more…

HPC Pioneer Gordon Bell Passed Away

May 22, 2024

Legendary computer scientist Gordon Bell passed away last Friday at his home in Coronado, CA. He was 89. The New York Times has a nice tribute piece. A long-time pioneer with Digital Equipment Corp, he pushed hard for de Read more…

ISC 2024 — A Few Quantum Gems and Slides from a Packed QC Agenda

May 22, 2024

If you were looking for quantum computing content, ISC 2024 was a good place to be last week — there were around 20 quantum computing related sessions. QC even earned a slide in Kathy Yelick’s opening keynote — Bey Read more…

Atos Outlines Plans to Get Acquired, and a Path Forward

May 21, 2024

Atos – via its subsidiary Eviden – is the second major supercomputer maker outside of HPE, while others have largely dropped out. The lack of integrators and Atos' financial turmoil have the HPC market worried. If Atos goes under, HPE will be the only major option for building large-scale systems. Read more…

Core42 Is Building Its 172 Million-core AI Supercomputer in Texas

May 20, 2024

UAE-based Core42 is building an AI supercomputer with 172 million cores which will become operational later this year. The system, Condor Galaxy 3, was announced earlier this year and will have 192 nodes with Cerebras Read more…

Google Announces Sixth-generation AI Chip, a TPU Called Trillium

May 17, 2024

On Tuesday May 14th, Google announced its sixth-generation TPU (tensor processing unit) called Trillium.  The chip, essentially a TPU v6, is the company's latest weapon in the AI battle with GPU maker Nvidia and clou Read more…

ISC 2024 Takeaways: Love for Top500, Extending HPC Systems, and Media Bashing

May 23, 2024

The ISC High Performance show is typically about time-to-science, but breakout sessions also focused on Europe's tech sovereignty, server infrastructure, storag Read more…

ISC 2024 — A Few Quantum Gems and Slides from a Packed QC Agenda

May 22, 2024

If you were looking for quantum computing content, ISC 2024 was a good place to be last week — there were around 20 quantum computing related sessions. QC eve Read more…

Atos Outlines Plans to Get Acquired, and a Path Forward

May 21, 2024

Atos – via its subsidiary Eviden – is the second major supercomputer maker outside of HPE, while others have largely dropped out. The lack of integrators and Atos' financial turmoil have the HPC market worried. If Atos goes under, HPE will be the only major option for building large-scale systems. Read more…

Google Announces Sixth-generation AI Chip, a TPU Called Trillium

May 17, 2024

On Tuesday May 14th, Google announced its sixth-generation TPU (tensor processing unit) called Trillium.  The chip, essentially a TPU v6, is the company's l Read more…

Europe’s Race towards Quantum-HPC Integration and Quantum Advantage

May 16, 2024

What an interesting panel, Quantum Advantage — Where are We and What is Needed? While the panelists looked slightly weary — their’s was, after all, one of Read more…

The Future of AI in Science

May 15, 2024

AI is one of the most transformative and valuable scientific tools ever developed. By harnessing vast amounts of data and computational power, AI systems can un Read more…

Some Reasons Why Aurora Didn’t Take First Place in the Top500 List

May 15, 2024

The makers of the Aurora supercomputer, which is housed at the Argonne National Laboratory, gave some reasons why the system didn't make the top spot on the Top Read more…

ISC 2024 Keynote: High-precision Computing Will Be a Foundation for AI Models

May 15, 2024

Some scientific computing applications cannot sacrifice accuracy and will always require high-precision computing. Therefore, conventional high-performance c Read more…

Synopsys Eats Ansys: Does HPC Get Indigestion?

February 8, 2024

Recently, it was announced that Synopsys is buying HPC tool developer Ansys. Started in Pittsburgh, Pa., in 1970 as Swanson Analysis Systems, Inc. (SASI) by John Swanson (and eventually renamed), Ansys serves the CAE (Computer Aided Engineering)/multiphysics engineering simulation market. Read more…

Nvidia H100: Are 550,000 GPUs Enough for This Year?

August 17, 2023

The GPU Squeeze continues to place a premium on Nvidia H100 GPUs. In a recent Financial Times article, Nvidia reports that it expects to ship 550,000 of its lat Read more…

Comparing NVIDIA A100 and NVIDIA L40S: Which GPU is Ideal for AI and Graphics-Intensive Workloads?

October 30, 2023

With long lead times for the NVIDIA H100 and A100 GPUs, many organizations are looking at the new NVIDIA L40S GPU, which it’s a new GPU optimized for AI and g Read more…

Atos Outlines Plans to Get Acquired, and a Path Forward

May 21, 2024

Atos – via its subsidiary Eviden – is the second major supercomputer maker outside of HPE, while others have largely dropped out. The lack of integrators and Atos' financial turmoil have the HPC market worried. If Atos goes under, HPE will be the only major option for building large-scale systems. Read more…

Choosing the Right GPU for LLM Inference and Training

December 11, 2023

Accelerating the training and inference processes of deep learning models is crucial for unleashing their true potential and NVIDIA GPUs have emerged as a game- Read more…

AMD MI3000A

How AMD May Get Across the CUDA Moat

October 5, 2023

When discussing GenAI, the term "GPU" almost always enters the conversation and the topic often moves toward performance and access. Interestingly, the word "GPU" is assumed to mean "Nvidia" products. (As an aside, the popular Nvidia hardware used in GenAI are not technically... Read more…

Nvidia’s New Blackwell GPU Can Train AI Models with Trillions of Parameters

March 18, 2024

Nvidia's latest and fastest GPU, codenamed Blackwell, is here and will underpin the company's AI plans this year. The chip offers performance improvements from Read more…

Some Reasons Why Aurora Didn’t Take First Place in the Top500 List

May 15, 2024

The makers of the Aurora supercomputer, which is housed at the Argonne National Laboratory, gave some reasons why the system didn't make the top spot on the Top Read more…

Leading Solution Providers

Contributors

Shutterstock 1606064203

Meta’s Zuckerberg Puts Its AI Future in the Hands of 600,000 GPUs

January 25, 2024

In under two minutes, Meta's CEO, Mark Zuckerberg, laid out the company's AI plans, which included a plan to build an artificial intelligence system with the eq Read more…

Eyes on the Quantum Prize – D-Wave Says its Time is Now

January 30, 2024

Early quantum computing pioneer D-Wave again asserted – that at least for D-Wave – the commercial quantum era has begun. Speaking at its first in-person Ana Read more…

The GenAI Datacenter Squeeze Is Here

February 1, 2024

The immediate effect of the GenAI GPU Squeeze was to reduce availability, either direct purchase or cloud access, increase cost, and push demand through the roof. A secondary issue has been developing over the last several years. Even though your organization secured several racks... Read more…

Shutterstock 1285747942

AMD’s Horsepower-packed MI300X GPU Beats Nvidia’s Upcoming H200

December 7, 2023

AMD and Nvidia are locked in an AI performance battle – much like the gaming GPU performance clash the companies have waged for decades. AMD has claimed it Read more…

The NASA Black Hole Plunge

May 7, 2024

We have all thought about it. No one has done it, but now, thanks to HPC, we see what it looks like. Hold on to your feet because NASA has released videos of wh Read more…

Intel Plans Falcon Shores 2 GPU Supercomputing Chip for 2026  

August 8, 2023

Intel is planning to onboard a new version of the Falcon Shores chip in 2026, which is code-named Falcon Shores 2. The new product was announced by CEO Pat Gel Read more…

GenAI Having Major Impact on Data Culture, Survey Says

February 21, 2024

While 2023 was the year of GenAI, the adoption rates for GenAI did not match expectations. Most organizations are continuing to invest in GenAI but are yet to Read more…

How the Chip Industry is Helping a Battery Company

May 8, 2024

Chip companies, once seen as engineering pure plays, are now at the center of geopolitical intrigue. Chip manufacturing firms, especially TSMC and Intel, have b Read more…

  • arrow
  • Click Here for More Headlines
  • arrow
HPCwire