This week at SC12, Italian cluster maker E4 Computer Engineering, launched a new series heterogeneous clusters, which pair an NVIDIA's ARM+GPU Tegra3 with a discrete Quadro GPU. We asked E4's Simone Tinti, who leads the HPC team at E4, to describe the new systems and talk about the advantage they offer to high performance computing users.

HPCwire: What does E4 Computer Engineering do, and who are your primary customers today?

Simone Tinti: E4 Computer Engineering new web site went online just before SC12 with a renewed look and a lot of contents) designs and manufactures high  performance computing and storage systems. We have a vast portfolio of solutions ranging from technical workstation to complete datacenter. E4 is also very active in providing storage solutions.

E4 Computer Engineering is currently operating in Europe, although CARMA solutions will be available worldwide. Our primary customer base is academia and research. For the past 7 years we have been one of the major supplier of CERN. At present we have more than 11,000 cores active in the CERN  datacenter --1700 computing nodes -- and more than 20 petabytes of storage.

Other relevant customers are ETHZ, EPFL, INFN, SISSA, ICTP,  Novartis, Merck, NATO and many more.
 
CARMA solutions are the results a E4 and SECO partnership. SECO is a European  designer  and manufacturer  of  high  integrated  board computers  and  systems  for  embedded applications. Founded in 1979 in Italy, SECO attention is focused on developing   innovative products with high performances efficiency, low power    consumption and increased functionality, offering in the meantime a short time-to-market. SECO has designed and manufactured the CARMA Devkit
 
HPCwire:  In a nutshell, could you briefly describe the three ARM-based solutions you are introducing and the application domains they are targeted at?
 
Tinti: We are introducing two platforms able to host carrier boards for the Qseven modules.

The CARMA microcluster, a 5U chassis, contains up to 8 CARMA blades  -- by default they have one NVIDIA Tegra 3 plus one NVIDIA Quadro 1000 -- and one x86-based  management node.

The CARMA cluster is a 3U chassis, containing up to 12 CARMA2 blades. These are high density blades, each one containing two CARMA blades for a total of two ARM CPUs plus two Quadro 1000 GPUs or 12 DARMA blades with four ARM CPUs per blade. You can, of course, mix DARMA and CARMA2 blades in the same chassis.

All blades (CARMA, CARMA2 , DARMA) are compliant with the Qseven standard so  the motherboard  -- or to be more accurate the carrier board -- contains only I/O devices like network, HDMI, SATA and so on.

The CPU component  -- actually a SoC containing CPU, RAM, Flash memory, graphics adapter -- may be selected from broad range of x86 architecture http://www.seco.com/it/itemlist/qseven/. Qseven technology  provides the highest flexibility while reducing engineering costs. In fact you can swap the CPU architecture re-using  the same carrier board without any modification.  SECO is a co-founder of Qseven consortium.

HPCwire: Regarding HPC applications, what are the advantages of the CARMA solutions compared to a more traditional x86/Tesla GPU cluster?  What niche are you filling with these ARM-based solutions?

Tinti: CARMA solutions provides a low power platform, ideal for applications that relies mainly on GPU computing power. With typical GPU computing systems you need a platform in the range of 250 to 350 watt, for example, a dual-Intel Xeon E5 or dual-AMD Opteron 6200 or 6300 in order to have your GPUs up and running. This is fine as long as a relevant part of the computation relies on CPUs, otherwise this is simply a waste a of power.

Usually GPUs are claimed to have a gigaflops per watt ratio of 3 (higher that the ~2 you can achieve on a BlueGene/Q systems, this is true only if you consider the GPU devices -- around 200 watts for  600 peak gigaflops. When you consider the whole platform this ratio drops down 1.2 /0.9 not far from a pure CPU systems as documented in the Green500.

With CARMA blades you need only 10 watts for the CPU, RAM, and flash drive; therefore most of the power -- 45 watts -- is dedicated to GPUs.

The “must” for exploiting CARMA solution is to have an application that is strongly focused on CUDA for CARMA and CARMA2 blades, or on big data/cloud for DARMA blades.

HPCwire:  What is the advantage of pairing a heterogeneous ARM plus GPU Tegra 3 with a discrete Quadro GPU?  What is the intended programming model for such an arrangement?

Tinti: With the current generation of ARM CPUs, you cannot address algorithms based on floating point arithmetic, therefore most scientific applications are excluded. NVIDIA Quadro GPU broadens the range of applications that can be addressed and gives a huge boost to performance.  CARMA is the one and the only platform available on the market that combines ARM’s low power CPUs with powerful NVIDIA GPUs.

HPCwire: Will developers with existing CUDA applications, run on an x86-Tesla set-up, be able to port their codes to the CARMA platform?

Yes, we provide a pre-configured cross compiling environment for ARM, CUDA, and MPI that makes this process very easy. Support services are also available. We are currently porting some applications, which will be disclosed soon. The systems come with the NVIDIA SDK and ORNL’s SHOC benchmark suite.

HPCwire: Are these clusters intended for production environments?

Tinti: The CARMA cluster is designed to be used in production environment, and provides a robust platform for a wide range of application: HPC, big data, and cloud.

The CARMA microcluster is designed to be a perfect development platform. It’s very quiet and can also be placed beside a desk. It could be used to create, but not for critical environments since a redundant power supply or remote management feature, like IPMI, are not available yet. Based upon the feedback we will receive at SC we will eventually release a more robust version of CARMA microcluster.

HPCwire:  Do you have customers with installed systems, or in the pipeline, for any of  the CARMA or DARMA systems?  What geographies do you intend to serve?

Tinti: More than 2000 CARMA dev kit has been sold so far to the most relevant research centers around the world. A lot of industries in different market such as animation, oil & gas, microelectronics, telecommunications, defense, and manufacturing have adopted it as a development platform. Unfortunately we cannot disclose the name, most of them are developing innovative applications and prefer to keep their privacy right now. Most of these customers are of course waiting for a platform ready for production, like the CARMA series.