SuperMUC Petascale System
SuperMUC is the name of the high-end supercomputer at the Leibniz-Rechenzentrum (Leibniz Supercomputing Centre) in Garching near Munich (the MUC suffix is borrowed from the Munich airport code). With more than 241,000 cores and a combined peak performance of the two installation phases of more than 6.8 Petaflop/s (=1015 Floating Point Operations per second), it is one of the fastest supercomputers in the world.
System purpose and target users
SuperMUC strengthens the position of Germany's Gauss Centre for Supercomputing in Europe by delivering outstanding compute power and integrating it into the European High Performance Computing ecosystem. With the operation of SuperMUC, LRZ will act as a European Centre for Supercomputing and will be a Tier-0 centre for PRACE, the Partnership for Advanced Computing in Europe. SuperMUC is available to all European researchers to expand the frontiers of science and engineering.
Figure: SuperMUC Phase 1 in the computer room.
System Configuration Details
LRZ's target for the architecture is a combination of a large number of thin and medium sized compute nodes with 32 GByte (Phase 1) and 64 GByte (Phase 2) of memory, respectively, and a smaller number of fat compute nodes with 256 GByte memory. The network interconnect between the nodes allows excellent scaling of parallel applications up to the level of more than 10,000 tasks.
SuperMUC consists of 18 Thin Node Islands based on Intel Sandy Bridge-EP processor technology, 6 Thin Node Islands based on Intel Haswell-EP processor technology and one Fat Node Island based on Intel Westmere-EX processor technology. Each Island contains more than 8,192 cores. All compute nodes within an individual Island are connected via a fully non-blocking Infiniband network (Phase 1: FDR10 for the Thin nodes of Phase 1, FDR14 for the Haswell nodes of Phase 2 and QDR for the Fat Nodes). Above the Island level, the pruned interconnect enables a bi-directional bi-section bandwidth ratio of 4:1 (intra-Island / inter-Island).
In addition, SuperMIC, a cluster of 32 Intel Sandy Bridge-EP nodes each having two Intel Xeon Phi accelerator cards installed, is also part of the SuperMUC system. Details on SuperMIC can be found under http://www.lrz.de/services/compute/supermuc/supermic/.
|Installation Phase||Phase 1||Phase 2|
|Fat Nodes||Thin Nodes||Many Cores Nodes||Haswell Nodes|
|System||BladeCenter HX5||IBM System x iDataPlex dx360M4||IBM System x iDataPlex dx360M4||Lenovo NeXtScale nx360M5 WCT|
|Processor Type|| Westmere-EX
Xeon E7-4870 10C
|Ivy-Bridge (IvyB) and Xeon Phi 5110P||Haswell Xeon Processor E5-2697 v3|
|Nominal Frequency [GHz]||2.4||2.7||1.05||2.62|
|Total Number of nodes||205||9216||32||3072|
|Total Number of cores||8,200||147,456||3,840 (Phi)||86,016|
|Total Peak Performance [PFlop/s]||0.078||3.2||0.064 (Phi)||3.58|
|Total Linpack Performance [PFlop/s]||0.065||2.897||n.a.||2.814|
|Total size of memory [TByte]||52||288||2.56||194|
|Total Number of Islands||1||18||1||6|
|Typical Power Consumption [MW]||< 2.3||~1.1|
|Nodes per Island||205||512||32||512|
|Processors per Node||4||2||
2 (IvyB) 2.6 GHz + 2 Phi 5110P
|Cores per Processor||10||8||8 (IvyB) + 60 (Phi)||14|
|Cores per Node||40||16||16 (host) + 120 (Phi)||28|
|Logical CPUs per Node (Hyperthreading)||80||32||32 (host) + 480 (Phi)||56|
|Memory and Caches|
|Memory per Core [GByte]
(typically available for applications)
|4 (host) + 2 x 0.13 (Phi)||2.3
|Size of shared Memory per node [GByte]||256||32||64 (host) + 2 x 8 (Phi)||64|
|Bandwidth to Memory per node [Gbyte/s]||136.4||102.4||Phi: 384||137|
|Level 3 Cache Size (shared) [Mbyte]||4x30||2x20||4x18|
|Level 2 Cache Size per core [kByte]||256||256||Phi: 512||256|
|Level 1 Cache Size [kByte]||32||32||32||32|
|Latency Access Memory||~160||~200|
|Level 3 Latency [cycles]||~ 30||36|
|Level 2 Latency [cycles]1||12||12|
|Level 1 Latency [cycles]1||4||4||4|
|Latency Access Memory||~160||~200|
|Technology||Infiniband QDR||Infiniband FDR10||Infiniband FDR10||Infiniband FDR14|
|Intra-Island Topology||non-blocking Tree||non-blocking Tree|
|Inter-Island Topology||Pruned Tree 4:1||n.a.||Pruned Tree 4:1|
|Bisection bandwidth of Interconnect [TByte/s]||12.5||5.1|
|Login Servers for users||2||7||1||5|
|Size of parallel storage (SCRATCH/WORK) [Pbyte]||15|
|Size of NAS storage (HOME) [PByte]||3.5 (+ 3.5 for replication)|
|Aggregated bandwidth to/from parallel storage [GByte/s]||250|
|Aggregated bandwidth to/from NAS storage [GByte/s]||12|
|Capacity of Archive and Backup Storage [PByte]||> 30|
|Operating System||Suse Linux Enterprise Server (SLES)|
|Parallel Filesystem for SCRATCH and WORK||IBM GPFS|
|File System for HOME||NetApp NAS|
|Archive and Backup Software||IBM TSM|
|System Management||xCat from IBM|
1:Latency is much longer, if data are also in L1 or L2 of other core.
2: With each new processor line, Intel introduces new architecture optimizations. The design of the “Haswell” architecture acknowledges that highly-parallel/vectorized applications place the highest load on the processor cores (requiring more power and thus generating more heat). While a CPU core is executing intensive vector tasks (AVX instructions), the clock speed may be reduced to keep the processor within its power limits (TDP). In effect, this may result in the processor running at a lower frequency than the “base” clock speed advertised for each model. For that reason, each “Haswell” processor model is assigned two “base” frequencies:
- AVX mode: due to the higher power requirements of AVX instructions, clock speeds may be somewhat lower while executing AVX instructions
- Non-AVX mode: while not executing AVX instructions, the processor will operate at what would traditionally be considered the “stock” frequency
Figure: Schematic view of SuperMUC Phase1
SuperMUC Phase1 and Phase2 are only loosely coupled through the GPFS and NAS File systems, used by both Phase 1 and Phase 2. It is not possible to run on single job across Phase1 and Phase2. The scheduling and job classes of Phase1 and Phase2 are different. However, Phase1 and Phase2 share the same programming environment.
Figure: Schematic view of SuperMUC Phase1 + Phase2.
Energy Efficiency by Warm Water cooling
SuperMUC uses a new, revolutionary form of warm water cooling developed by IBM. Active components like processors and memory are directly cooled with water that can have an inlet temperature of up to 40 degrees Celsius. This "High Temperature Liquid Cooling" together with very innovative system software cuts the energy consumption of the system up to 40%. In addition, LRZ buildings are heated re-using this energy.
Why "warm" water cooling?
Typically water used in data centers has an inlet temperature of approx 16 degrees Celsius and, after leaving the system, an outlet temperature of approx. 20 degrees Celsius. To make water with 16 degrees Celsius requires complex and energy-hungry cooling equipment. At the same time there is hardly any use for the warmed-up water as it is too cold to be uses in any technical processes.
SuperMUC allows an increased inlet temperature. It is easily possible to provide water having up to 40 degrees Celsius using simple "free-cooling" equipment as outside temperatures in Germany hardly ever exceed 35 degrees Celsius. At the same time the outlet water can be made quite hot (up to 70 degrees Celsius) and re-used in other technical processes - for example to heat buildings or in other technical processes.
By reducing the number of cooling components and using free cooling LRZ expects to save several millions of Euros in cooling costs over the 5-year lifetime of the system.
SuperMUC has a powerful I/O-Subsystem which helps to process large amounts of data generated by simulations.
Home file systems
Permanent storage for data and programs is provided by a 16-node NAS cluster from NetApp. This primary cluster has a capacity of 3.5 Petabytes and has demonstrated an aggregated throughput of more than 12 GB/s using NFSv3. Netapp's Ontap 8 "Cluster-mode" provides a single namespace for several hundred project volumes on the system. Users can access multiple snapshots of data in their home directories.
Data is regularly replicated to a separate 4-node Netapp cluster with another 3.5 PB of storage for recovery purposes. Replication uses Snapmirror-technology and runs with up to 2 GB/s in this setup.
Storage hardware consists of >3,400 SATA-Disks with 2 TB each, protected by double-parity RAID and integrated checksums.
Work and Scratch areas
For high-performance I/O, IBM's General Parallel File System (GPFS) with 12 PB of capacity and an aggregated throughput of 250 GB/s is available.
Tape backup and archives
LRZ's tape backup and archive systems based on TSM (Tivoli Storage Manager) from IBM are used for or archiving and backup. They have been extended to provide more than 30 Petabytes of capacity to the users of SuperMUC. Digital long-term archives help to preserve results of scientific work on SuperMUC. User archives are also transferred to a disaster recovery site.
Visualization and Support systems
SuperMUC is connected to powerful visualization systems: the new LRZ office building houses a large 4K stereoscopic powerwall as well as a 5-sided CAVE artificial virtual reality environment.