SNAC Small NSC, 2018


This round has been closed as all proposals have been handled.

More information about this round is available at


Resource Centre Total
Available Unit Note
Tetralith NSC 161 200 x 1000 core-h/month
Tetralith,, runs a CentOS 7 version of the NSC Cluster Software Environment. This means that most things are very familiar to Triolith users. You still use Slurm (e.g sbatch, interactive, ...) to submit your jobs. ThinLinc is available on the login nodes. Applications are selected using "module". All Tetralith compute nodes have 32 CPU cores. There will be 1832 "thin" nodes with 96 GiB of primary memory (RAM) and 60 "fat" nodes with 384 GiB. Each compute node will have a local SSD disk where applications can store temporary files (approximately 200GB per node). All Tetralith nodes are interconnected with a 100 Gbps Intel Omni-Path network which is also used to connect the existing storage. The Omni-Path network works in a similar way to the FDR Infiniband network in Triolith (e.g with a fat-tree topology). The Tetralith installation will take place in two phases. The first phase consist of 644 nodes and have a capacity that exceeds the current computing capacity of Triolith. The first phase was made available to users on August 23, 2018. Triolith was turned off September 21, 2018. After this, the second phase of the Tetralith installation will begin. NSC plans to have the entire Tetralith in operation no later than December 31st (i.e for the next round of SNAC Large projects.)
Triolith NSC 164 200 x 1000 core-h/month Triolith has been replaced by Tetralith.
Triolith has been replaced with a new system named Tetralith running a CentOS 7 version of the NSC Cluster Software Environment. Awarded Triolith allocations has been transferred to Tetralith and users migrated. The Tetralith installation takes place in two stages. The first stage has a capacity that exceeds the current computing capacity of Triolith and was available from August 23, 2018. The second part is installed after Triolith is decommissioned and dismounted. NSC plan to have the entire Tetralith in operation by November. Existing centre storage remains and is connected to Tetralith.

Triolith ( was a capability cluster with a total of 24320 cores and a peak performance of 428 Tflops/s. However, Triolith was shrunk by 576 nodes on April 3rd, 2017 as a result of a delay in funding a replacement system and now has a peak performance of 260 Teraflop/sec and 16,368 compute cores. It is equipped with a fast interconnect for high performance for parallel applications. The operating system is CentOS 6.x x86_64. Each of the 1520 (now 944) HP SL230s compute servers is equipped with two Intel E5-2660 (2.2 GHz Sandybridge) processors with 8 cores each (i.e. 16 cores per compute server). 56 of the compute servers have 128 GiB memory each and the remaining 888 have 32 GiB each. The fast interconnect is Infiniband from Mellanox (FDR IB, 56 Gb/s) in a 2:1 blocking configuration. Triolith have been replaced with a new system, Tetralith, that was made available to users on August 23, 2018. NSC currently plan to keep Triolith in operation and available to users until September 21st, 2018. After that, Triolith will be permanently shut down and decommissioned.

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