HPCwire: Compilers and More: The Dangers of COTS Supercomputing

The Leading Source for Global News and Information Covering the Ecosystem of High Productivity Computing

HPCwire >> Features

April 04, 2008

Compilers and More: The Dangers of COTS Supercomputing

by Michael Wolfe, Compiler Engineer, The Portland Group, Inc.

Page: 1 of 2
1 | 2 All »

One of the last events at Supercomputing 2007 (SC07) was a panel titled "(Super)Computing on FPGAs, GPUs, Cell and Other Exotic Architectures" on Friday morning.

Jack Dongarra (Univ. Tennessee and ORNL) said that the HPC ecosystem is out of balance; we've invested heavily in hardware development, and now we need to invest more heavily in software tools and methods to use the hardware. Rob Pennington (NCSA), the panel moderator, said that the tools will appear when there are enough of these systems out there that the vendors can make money at it. I disagree with both these statements.

In response to Jack Dongarra's statement, I agree that the investment in software tools for high performance computing has been lacking, but it's been equally limited for hardware. While I didn't do a comprehensive survey on the exhibit show floor at SC07 in Reno, almost all the machines displayed there were built from COTS (commodity off-the-shelf) processors, mostly x86-64 from Intel and AMD, some PowerPC from IBM, and in some cases, SPARC and MIPS. Any innovation seems to be in the interconnect, packaging, power, and cooling. Notable exceptions are traditional vector supercomputers from NEC and Cray, and the ClearSpeed accelerators. It seems the HPC market can't support processor development; current process technology is just too expensive.

There is a great deal of hype and promise for accelerators. However, even here we depend on the commodity market to drive the technology and development, and hope to gain what benefit we can. We are in the dangerous position of depending on the scraps that fall off the PlayStation table -- and if they take their picnic and go somewhere else, we're in real trouble. If you think this is silly, try asking NVIDIA to add a feature to their graphics cards that will speed up your application but will hurt graphics performance. I can hear the laughter already.

Of more concern is what may happen with the mainstream processor business. AMD and Intel have already announced quad-core chips, with plans for eight and more. David Scott (Intel), at a focus session in the HP-CAST user group meeting the Saturday prior to SC07, noted that if you are willing to give up single-core performance, you can put a lot of cores on a single chip, with today's technology. There are many applications where such a strategy makes a great deal of sense: web services, database transactions -- anything that responds to many small, independent requests. Think Google. In fact, most computing might fall into that market, where single thread performance doesn't matter, only the total throughput.

But not HPC. Imagine having to expose and manage five or ten times more parallelism just to deliver the same performance as a single thread today. To get actual performance improvement, you need yet another factor of parallelism.

But guess who will win that architecture argument.

As for software, the dominant programming model for parallel computers hasn't changed in almost 20 years, except to replace PVM with MPI. (I count substituting C or C++ for Fortran as a giant step sideways.) Perhaps this is inevitable. Douglass Post (DoD, HPCMP) pointed out at the SC07 panel that the lifetime of a large code is 20 to 30 years, whereas the lifetime of any large HPC system is more like 3 to 4 years. Portability, including performance portability, is more important than peak performance on any one system.

One of PGI's consultants told us that today's programmers like the MPI model, if only because it makes their lives easier. They can concentrate on porting and tuning today's algorithms and programs to MPI, which is a lot of work, but not too mentally demanding. If we move to a model where parallel programming is less work, they'll have to take on the task of finding better parallel algorithms, which is much more challenging.

So, to correct Jack Dongarra, the problem isn't balance. The HPC ecosystem is in perfect balance, with little investment and innovation in both hardware and software. We're in a precarious position now. The community is able to benefit from the COTS market, but it's anyone's guess how long we'll be able to thrive there.

Page: 1 of 2
1 | 2 All »

Article Tools

Share Options

(Digg, Technorati, more)

Subscribe

Subscribe to HPCwire

Discussion

There are 0 discussion items posted.

Join the Discussion

You must be a registered user in order to comment on HPCwire stories.

Members enjoy:

	Access to Special Content, including Podcasts, Webcasts, and Whitepapers and more!
	Ability to take an active role in the discussions that are shaping the HPC technology discipline!
	Special offers available only to HPCwire members!

Become a Registered User Today!

Registered Users Log in Here to Comment

Email Address:	Password (case sensitive)

Remember me	Forgot Password?

RSS Feeds

Feeds by Topic

Feeds by Industry

Feeds by Content Type

Top Headlines

Intel Partners See 'Easy' Upgrade Path With Xeon 5600 Chips

Mar 18 | ChannelWeb | Westmere parts already showing up in HPC machines. Read more...

AMD: OEMs primed for Opteron 6100s

Mar 17 | The Register | But what about the tier ones? Read more...

Arrival of the Desktop Supercomputer

Mar 17 | Cadalyst Magazine | A new generation of workstations is changing the nature of technical computing. Read more...

Scheduling HPC In The Cloud

Mar 17 | Linux Magazine | Latest iteration of Sun Grid Engine able to tap into Cloud. Read more...

Tailoring Medicine with Supercomputers

Mar 16 | Bio-IT World | Biotech firm builds genetic models from patient data. Read more...

Read more headlines...

Featured Whitepapers

Virtualization for Aggregation And The vSMP Architecture™

Jan 12 | | In-depth look at vSMP Foundation server virtualization technology, technical implementation, use cases and capabilities. The technical whitepaper provides an architectural overview and details on the three vSMP Foundation products: vSMP Foundation for SMP, vSMP Foundation for Cluster and vSMP Foundation for Cloud.

Copper Cable Technologies for High Performance Computing

Jan 18 | | This white paper discusses Gore’s copper cable assemblies, and how they continue to exceed the standards for providing reliable, cost-effective solutions for high-performance computer applications.

View the White Paper Library

Multimedia

Webcast: Virtualized Data Center Roundtable

Join this online panel discussion for live Q&A with leading industry experts, analysts, and end-users to discuss the latest innovations, best practices, barriers to implementation, and measurable benefits of server virtualization with a particular focus on today's real world solutions.

Webcast: Watch SC09 Birds of a Feather Video: Scalable Fault-Tolerant HPC Supercomputers

Learn about scalable fault-tolerant architectures and examples of energy efficient and scalable supercomputing clusters using dual QDR InfiniBand to combine capacity computing with network failover capabilities with the help of programming languages such as MPI and a robust Linux cluster management package.

Webcast: High Performance Computing for a Smarter Planet

LIVE@SCO9: The IBM team discusses new innovations in hardware, software and services that help clients better understand their workloads and get insight from their R&D efforts. Technology demonstrations include the soon-to-be-released Power7 HPC processor, the DCS990 system with 2.4 petabytes of storage, the xCAT management tool, secure HPC cloud computing and more. Winners of two HPCwire Readers' and Editors’ Choice Awards! Take the IBM virtual tour at SC09 or more information go online to: http://www-03.ibm.com/systems/deepcomputing/sc09.html