compute-nodes.md

# Compute Nodes

## Nodes Configuration

Anselm is cluster of x86-64 Intel based nodes built on Bull Extreme Computing bullx technology. The cluster contains four types of compute nodes.

### Compute Nodes Without Accelerator

* 180 nodes
* 2880 cores in total
* two Intel Sandy Bridge E5-2665, 8-core, 2.4GHz processors per node
* 64 GB of physical memory per node
* one 500GB SATA 2,5” 7,2 krpm HDD per node
* bullx B510 blade servers
* cn[1-180]

### Compute Nodes With GPU Accelerator

* 23 nodes
* 368 cores in total
* two Intel Sandy Bridge E5-2470, 8-core, 2.3GHz processors per node
* 96 GB of physical memory per node
* one 500GB SATA 2,5” 7,2 krpm HDD per node
* GPU accelerator 1x NVIDIA Tesla Kepler K20 per node
* bullx B515 blade servers
* cn[181-203]

### Compute Nodes With MIC Accelerator

* 4 nodes
* 64 cores in total
* two Intel Sandy Bridge E5-2470, 8-core, 2.3GHz processors per node
* 96 GB of physical memory per node
* one 500GB SATA 2,5” 7,2 krpm HDD per node
* MIC accelerator 1x Intel Phi 5110P per node
* bullx B515 blade servers
* cn[204-207]

### Fat Compute Nodes

* 2 nodes
* 32 cores in total
* 2 Intel Sandy Bridge E5-2665, 8-core, 2.4GHz processors per node
* 512 GB of physical memory per node
* two 300GB SAS 3,5”15krpm HDD (RAID1) per node
* two 100GB SLC SSD per node
* bullx R423-E3 servers
* cn[208-209]

![](../img/bullxB510.png)
**Figure Anselm bullx B510 servers**

### Compute Nodes Summary

  |Node type|Count|Range|Memory|Cores|[Access](resources-allocation-policy/)|
  |---|---|---|---|---|---|
  |Nodes without accelerator|180|cn[1-180]|64GB|16 @ 2.4Ghz|qexp, qprod, qlong, qfree|
  |Nodes with GPU accelerator|23|cn[181-203]|96GB|16 @ 2.3Ghz|qgpu, qprod|
  |Nodes with MIC accelerator|4|cn[204-207]|96GB|16 @ 2.3GHz|qmic, qprod|
  |Fat compute nodes|2|cn[208-209]|512GB|16 @ 2.4GHz|qfat, qprod|

## Processor Architecture

Anselm is equipped with Intel Sandy Bridge processors Intel Xeon E5-2665 (nodes without accelerator and fat nodes) and Intel Xeon E5-2470 (nodes with accelerator). Processors support Advanced Vector Extensions (AVX) 256-bit instruction set.

### Intel Sandy Bridge E5-2665 Processor

* eight-core
* speed: 2.4 GHz, up to 3.1 GHz using Turbo Boost Technology
* peak performance:  19.2 GFLOP/s per core
* caches:
  * L2: 256 KB per core
  * L3: 20 MB per processor
* memory bandwidth at the level of the processor: 51.2 GB/s

### Intel Sandy Bridge E5-2470 Processor

* eight-core
* speed: 2.3 GHz, up to 3.1 GHz using Turbo Boost Technology
* peak performance:  18.4 GFLOP/s per core
* caches:
  * L2: 256 KB per core
  * L3: 20 MB per processor
* memory bandwidth at the level of the processor: 38.4 GB/s

Nodes equipped with Intel Xeon E5-2665 CPU have set PBS resource attribute cpu_freq = 24, nodes equipped with Intel Xeon E5-2470 CPU have set PBS resource attribute cpu_freq = 23.

```bash
$ qsub -A OPEN-0-0 -q qprod -l select=4:ncpus=16:cpu_freq=24 -I
```

In this example, we allocate 4 nodes, 16 cores at 2.4GHhz per node.

Intel Turbo Boost Technology is used by default,  you can disable it for all nodes of job by using resource attribute cpu_turbo_boost.

```bash
    $ qsub -A OPEN-0-0 -q qprod -l select=4:ncpus=16 -l cpu_turbo_boost=0 -I
```

## Memory Architecture

### Compute Node Without Accelerator

* 2 sockets
* Memory Controllers are integrated into processors.
  * 8 DDR3 DIMMs per node
  * 4 DDR3 DIMMs per CPU
  * 1 DDR3 DIMMs per channel
  * Data rate support: up to 1600MT/s
* Populated memory: 8 x 8 GB DDR3 DIMM 1600 MHz

### Compute Node With GPU or MIC Accelerator

* 2 sockets
* Memory Controllers are integrated into processors.
  * 6 DDR3 DIMMs per node
  * 3 DDR3 DIMMs per CPU
  * 1 DDR3 DIMMs per channel
  * Data rate support: up to 1600MT/s
* Populated memory: 6 x 16 GB DDR3 DIMM 1600 MHz

### Fat Compute Node

* 2 sockets
* Memory Controllers are integrated into processors.
  * 16 DDR3 DIMMs per node
  * 8 DDR3 DIMMs per CPU
  * 2 DDR3 DIMMs per channel
  * Data rate support: up to 1600MT/s
* Populated memory: 16 x 32 GB DDR3 DIMM 1600 MHz