Multicore Watershed

By Michael Feldman

March 4, 2010

As many industry watchers have noted, including me, the next few months will see the introduction of a raft of new x86 server chips that offer between 6 and 12 cores. Although both Intel and AMD have already fielded 6-core processors (“Dunnington” for Intel and “Istanbul” for AMD), the new Xeon and Opterons will set some new expectations in the x86 server chip arena.

For one thing, the “multi” in multicore is about to become a lot more meaningful. Instead of simply doubling the core count, which was the model in the past, when the industry moved en masse from uni-core to dual-core to quad-core, we’re now going to see processors with 2, 4, 6, 8, and 12 cores filling different niches in the server space.

This month, Intel is expected to roll out its 6-core Westmere EP processor aimed at dual-socket platforms. For 4-socket systems and above, the 8-core Nehalem EX is expected before mid-year. Intel is also planning on a faster clocked 6-core Nehalem EX variant, which is targeted especially for the HPC market. Meanwhile, AMD is set to launch its 8- and 12-core Magny Cours Opterons at about the same time as the first Westmere chips launch. Magny-Cours, though, will support both 2- and 4-socket servers.

Given that diversity, server makers will have a lot more choice on how they want to balance FLOPs with memory capacity, memory bandwidth, and I/O in different product niches. This is especially true for HPC, where the memory wall problem is particularly prominent. In fact, in this post-quad-core era it’s worth remembering the 2009 Sandia study that suggested performance would drop for certain data-intensive apps when the underlying platform moved beyond eight cores:

A Sandia team simulated key algorithms for deriving knowledge from large data sets. The simulations show a significant increase in speed going from two to four multicores, but an insignificant increase from four to eight multicores. Exceeding eight multicores causes a decrease in speed. Sixteen multicores perform barely as well as two, and after that, a steep decline is registered as more cores are added.

That suggests that the most likely consequence of core proliferation will be greater emphasis on memory capacity and bandwidth per node. As processors have added performance, the memory bytes per flop and bytes/sec per flop ratios have been dropping, leaving a lot of unused performance on the chip. To counter that, we’re starting to see a trend back to big-node, shared memory systems. Frankly, most of the commercial solutions for x86-based systems are more focused on increasing memory capacity, rather than bandwidth, given that the latter is far more difficult to accomplish without design help at the CPU level. Nevertheless, increasing memory can indirectly help the bandwidth issue, since aggregate access increases as you add more RAM.

The move to bigger memory machines has already begun. NCSA is getting reading to install Ember, a large-scale shared memory SGI UV Altix super. That machine is going to be used for computational chemistry as well as solid and fluid dynamics research. ScaleMP, which uses its vSMP technology to concoct virtual SMPs, has had a number of wins lately, include the Gordon cluster at the San Diego Supercomputing Center. Although that machine is best known for its use of flash memory, the vSMP technology is used to build “supernodes” that can access as much as 2 TB of RAM. Relative newcomer 3Leaf Systems recently announced Florida State University will deploy the company’s “fabric computing” technology to aggregate multiple Opteron-based nodes into virtual shared memory servers. Finally, although not aimed at HPC, IBM just unveiled its eX5 servers, which allows users to expand RAM to 1.5 TB per two-socket machine.

The burgeoning core count also raises a sort of existential question for a lot of HPC users. In a Linux Magazine article, Douglas Eadline noted that since more than half of HPC apps use 32 cores or fewer (according to both IDC research and a Cluster Monkey survey), it’s possible low-end HPC work will migrate from clusters to single nodes. In that case, multi-socketed workstations could end up replacing traditional clusters.

Well, the sweet spot of such workstations is still dual-socket systems (as it is for servers), so we’ll really have to wait until 16-core chips hit the streets next year to answer that question. On the other hand, considering that the latest GPUs from AMD and NVIDIA (especially the upcoming Fermi processors) can take the place of multiple high-end CPUs for a range of HPC workloads, we may not need dozens of x86 cores to push a lot of low-end supercomputing onto the desktop. In fact, the presence of general-purpose GPUs makes the use of double-digit core counts somewhat superfluous in these cases, unless someone can figure out a way match up graphics processors with CPU cores.

One final thought. When considering how multicore CPUs are distorting system balance, it’s tempting to get hung up on efficiency metrics and maximizing hardware resources. But as John Gustafson has reminded us: “System balance is not about bytes per flops/s, mass storage/RAM, or any such ratios. It never has been. System balance means adding something to the design such that the percent improvement in value (performance, reliability, or whatever) is greater than the percent improvement in the total cost of ownership. A system is perfectly balanced when no further such improvements are possible.”

Subscribe to HPCwire's Weekly Update!

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

Do Cryptocurrencies Have a Part to Play in HPC?

February 22, 2018

It’s easy to be distracted by news from the US, China, and now the EU on the state of various exascale projects, but behind the vinyl-wrapped cabinets and well-groomed sales execs are an army of Excel-wielding PMO and Read more…

By Chris Downing

HOKUSAI’s BigWaterfall Cluster Extends RIKEN’s Supercomputing Performance

February 21, 2018

RIKEN, Japan’s largest comprehensive research institution, recently expanded the capacity and capabilities of its HOKUSAI supercomputer, a key resource managed by the institution’s Advanced Center for Computing and C Read more…

By Ken Strandberg

Neural Networking Shows Promise in Earthquake Monitoring

February 21, 2018

A team of Harvard University and MIT researchers report their new neural networking method for monitoring earthquakes is more accurate and orders of magnitude faster than traditional approaches. Read more…

By John Russell

HPE Extreme Performance Solutions

Experience Memory & Storage Solutions that will Transform Your Data Performance

High performance computing (HPC) has revolutionized the way we harness insight, leading to a dramatic increase in both the size and complexity of HPC systems. Read more…

HPE Wins $57 Million DoD Supercomputing Contract

February 20, 2018

Hewlett Packard Enterprise (HPE) today revealed details of its massive $57 million HPC contract with the U.S. Department of Defense (DoD). The deal calls for HPE to provide the DoD High Performance Computing Modernizatio Read more…

By Tiffany Trader

HOKUSAI’s BigWaterfall Cluster Extends RIKEN’s Supercomputing Performance

February 21, 2018

RIKEN, Japan’s largest comprehensive research institution, recently expanded the capacity and capabilities of its HOKUSAI supercomputer, a key resource manage Read more…

By Ken Strandberg

Neural Networking Shows Promise in Earthquake Monitoring

February 21, 2018

A team of Harvard University and MIT researchers report their new neural networking method for monitoring earthquakes is more accurate and orders of magnitude faster than traditional approaches. Read more…

By John Russell

HPE Wins $57 Million DoD Supercomputing Contract

February 20, 2018

Hewlett Packard Enterprise (HPE) today revealed details of its massive $57 million HPC contract with the U.S. Department of Defense (DoD). The deal calls for HP Read more…

By Tiffany Trader

Fluid HPC: How Extreme-Scale Computing Should Respond to Meltdown and Spectre

February 15, 2018

The Meltdown and Spectre vulnerabilities are proving difficult to fix, and initial experiments suggest security patches will cause significant performance penal Read more…

By Pete Beckman

Brookhaven Ramps Up Computing for National Security Effort

February 14, 2018

Last week, Dan Coats, the director of Director of National Intelligence for the U.S., warned the Senate Intelligence Committee that Russia was likely to meddle in the 2018 mid-term U.S. elections, much as it stands accused of doing in the 2016 Presidential election. Read more…

By John Russell

AI Cloud Competition Heats Up: Google’s TPUs, Amazon Building AI Chip

February 12, 2018

Competition in the white hot AI (and public cloud) market pits Google against Amazon this week, with Google offering AI hardware on its cloud platform intended Read more…

By Doug Black

Russian Nuclear Engineers Caught Cryptomining on Lab Supercomputer

February 12, 2018

Nuclear scientists working at the All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF) have been arrested for using lab supercomputing resources to mine crypto-currency, according to a report in Russia’s Interfax News Agency. Read more…

By Tiffany Trader

The Food Industry’s Next Journey — from Mars to Exascale

February 12, 2018

Global food producer and one of the world's leading chocolate companies Mars Inc. has a unique perspective on the impact that exascale computing will have on the food industry. Read more…

By Scott Gibson, Oak Ridge National Laboratory

Inventor Claims to Have Solved Floating Point Error Problem

January 17, 2018

"The decades-old floating point error problem has been solved," proclaims a press release from inventor Alan Jorgensen. The computer scientist has filed for and Read more…

By Tiffany Trader

Japan Unveils Quantum Neural Network

November 22, 2017

The U.S. and China are leading the race toward productive quantum computing, but it's early enough that ultimate leadership is still something of an open questi Read more…

By Tiffany Trader

AMD Showcases Growing Portfolio of EPYC and Radeon-based Systems at SC17

November 13, 2017

AMD’s charge back into HPC and the datacenter is on full display at SC17. Having launched the EPYC processor line in June along with its MI25 GPU the focus he Read more…

By John Russell

Researchers Measure Impact of ‘Meltdown’ and ‘Spectre’ Patches on HPC Workloads

January 17, 2018

Computer scientists from the Center for Computational Research, State University of New York (SUNY), University at Buffalo have examined the effect of Meltdown Read more…

By Tiffany Trader

IBM Begins Power9 Rollout with Backing from DOE, Google

December 6, 2017

After over a year of buildup, IBM is unveiling its first Power9 system based on the same architecture as the Department of Energy CORAL supercomputers, Summit a Read more…

By Tiffany Trader

Nvidia Responds to Google TPU Benchmarking

April 10, 2017

Nvidia highlights strengths of its newest GPU silicon in response to Google's report on the performance and energy advantages of its custom tensor processor. Read more…

By Tiffany Trader

Fast Forward: Five HPC Predictions for 2018

December 21, 2017

What’s on your list of high (and low) lights for 2017? Volta 100’s arrival on the heels of the P100? Appearance, albeit late in the year, of IBM’s Power9? Read more…

By John Russell

Russian Nuclear Engineers Caught Cryptomining on Lab Supercomputer

February 12, 2018

Nuclear scientists working at the All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF) have been arrested for using lab supercomputing resources to mine crypto-currency, according to a report in Russia’s Interfax News Agency. Read more…

By Tiffany Trader

Leading Solution Providers

Chip Flaws ‘Meltdown’ and ‘Spectre’ Loom Large

January 4, 2018

The HPC and wider tech community have been abuzz this week over the discovery of critical design flaws that impact virtually all contemporary microprocessors. T Read more…

By Tiffany Trader

Perspective: What Really Happened at SC17?

November 22, 2017

SC is over. Now comes the myriad of follow-ups. Inboxes are filled with templated emails from vendors and other exhibitors hoping to win a place in the post-SC thinking of booth visitors. Attendees of tutorials, workshops and other technical sessions will be inundated with requests for feedback. Read more…

By Andrew Jones

How Meltdown and Spectre Patches Will Affect HPC Workloads

January 10, 2018

There have been claims that the fixes for the Meltdown and Spectre security vulnerabilities, named the KPTI (aka KAISER) patches, are going to affect applicatio Read more…

By Rosemary Francis

GlobalFoundries, Ayar Labs Team Up to Commercialize Optical I/O

December 4, 2017

GlobalFoundries (GF) and Ayar Labs, a startup focused on using light, instead of electricity, to transfer data between chips, today announced they've entered in Read more…

By Tiffany Trader

Tensors Come of Age: Why the AI Revolution Will Help HPC

November 13, 2017

Thirty years ago, parallel computing was coming of age. A bitter battle began between stalwart vector computing supporters and advocates of various approaches to parallel computing. IBM skeptic Alan Karp, reacting to announcements of nCUBE’s 1024-microprocessor system and Thinking Machines’ 65,536-element array, made a public $100 wager that no one could get a parallel speedup of over 200 on real HPC workloads. Read more…

By John Gustafson & Lenore Mullin

Flipping the Flops and Reading the Top500 Tea Leaves

November 13, 2017

The 50th edition of the Top500 list, the biannual publication of the world’s fastest supercomputers based on public Linpack benchmarking results, was released Read more…

By Tiffany Trader

V100 Good but not Great on Select Deep Learning Aps, Says Xcelerit

November 27, 2017

Wringing optimum performance from hardware to accelerate deep learning applications is a challenge that often depends on the specific application in use. A benc Read more…

By John Russell

SC17: Singularity Preps Version 3.0, Nears 1M Containers Served Daily

November 1, 2017

Just a few months ago about half a million jobs were being run daily using Singularity containers, the LBNL-founded container platform intended for HPC. That wa Read more…

By John Russell

  • arrow
  • Click Here for More Headlines
  • arrow
Share This