# Hardware Overview The Anselm cluster consists of 209 computational nodes named cn[1-209] of which 180 are regular compute nodes, 23 are GPU Kepler K20 accelerated nodes, 4 are MIC Xeon Phi 5110P accelerated nodes, and 2 are fat nodes. Each node is a powerful x86-64 computer, equipped with 16 cores (two eight-core Intel Sandy Bridge processors), at least 64 GB of RAM, and a local hard drive. User access to the Anselm cluster is provided by two login nodes login[1,2]. The nodes are interlinked through high speed InfiniBand and Ethernet networks. All nodes share a 320 TB /home disk for storage of user files. The 146 TB shared /scratch storage is available for scratch data. The Fat nodes are equipped with a large amount (512 GB) of memory. Virtualization infrastructure provides resources to run long-term servers and services in virtual mode. Fat nodes and virtual servers may access 45 TB of dedicated block storage. Accelerated nodes, fat nodes, and virtualization infrastructure are available [upon request][a] from a PI. Schematic representation of the Anselm cluster. Each box represents a node (computer) or storage capacity:  The cluster compute nodes cn[1-207] are organized within 13 chassis. There are four types of compute nodes: * 180 compute nodes without an accelerator * 23 compute nodes with a GPU accelerator - an NVIDIA Tesla Kepler K20m * 4 compute nodes with a MIC accelerator - an Intel Xeon Phi 5110P * 2 fat nodes - equipped with 512 GB of RAM and two 100 GB SSD drives [More about Compute nodes][1]. GPU and accelerated nodes are available upon request, see the [Resources Allocation Policy][2]. All of these nodes are interconnected through fast InfiniBand and Ethernet networks. [More about the Network][3]. Every chassis provides an InfiniBand switch, marked **isw**, connecting all nodes in the chassis, as well as connecting the chassis to the upper level switches. All of the nodes share a 360 TB /home disk for storage of user files. The 146 TB shared /scratch storage is available for scratch data. These file systems are provided by the Lustre parallel file system. There is also local disk storage available on all compute nodes in /lscratch. [More about Storage][4]. User access to the Anselm cluster is provided by two login nodes login1, login2, and data mover node dm1. [More about accessing the cluster][5]. The parameters are summarized in the following tables: | **In general** | | | ------------------------------------------- | -------------------------------------------- | | Primary purpose | High Performance Computing | | Architecture of compute nodes | x86-64 | | Operating system | Linux (CentOS) | | [**Compute nodes**][1] | | | Total | 209 | | Processor cores | 16 (2 x 8 cores) | | RAM | min. 64 GB, min. 4 GB per core | | Local disk drive | yes - usually 500 GB | | Compute network | InfiniBand QDR, fully non-blocking, fat-tree | | w/o accelerator | 180, cn[1-180] | | GPU accelerated | 23, cn[181-203] | | MIC accelerated | 4, cn[204-207] | | Fat compute nodes | 2, cn[208-209] | | **In total** | | | Total theoretical peak performance (Rpeak) | 94 TFLOP/s | | Total max. LINPACK performance (Rmax) | 73 TFLOP/s | | Total amount of RAM | 15.136 TB | | Node | Processor | Memory | Accelerator | | ---------------- | --------------------------------------- | ------ | -------------------- | | w/o accelerator | 2 x Intel Sandy Bridge E5-2665, 2.4 GHz | 64 GB | - | | GPU accelerated | 2 x Intel Sandy Bridge E5-2470, 2.3 GHz | 96 GB | NVIDIA Kepler K20m | | MIC accelerated | 2 x Intel Sandy Bridge E5-2470, 2.3 GHz | 96 GB | Intel Xeon Phi 5110P | | Fat compute node | 2 x Intel Sandy Bridge E5-2665, 2.4 GHz | 512 GB | - | For more details, refer to [Compute nodes][1], [Storage][4], and [Network][3]. [1]: compute-nodes.md [2]: ../general/resources-allocation-policy.md [3]: network.md [4]: storage.md [5]: ../general/shell-and-data-access.md [a]: https://support.it4i.cz/rt