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Nodes Overview

internals

Apocrita runs a variety of different job types, and the cluster is comprised of different node types and queues to accommodate this. Unless you have a specific technical reason, you should avoid selecting a specific node type to run your job on. Some nodes are restricted depending on the source of funding.

The following nodes are open access, allowing jobs from any user.

Open Access Required variables Count Cores RAM Accessible RAM Arch
ddy 56 48 384GB ~362GB Intel
emf highmem 14 24 768GB ~741GB Intel
nxv 34 32 256GB ~242GB Intel
nxg gpu 4 32 256GB ~242GB Intel
sbg (ampere) gpu 1 48 384GB ~365GB Intel
sbg (volta) gpu 3 32 384GB ~365GB Intel
sdv infiniband=sdv-i 32 24 192GB ~176GB Intel
sdx 52 36 384GB ~362GB Intel
srm highmem 2 36 768GB ~741GB Intel
Total 198 7096 71.2TB

The following nodes are restricted to specific groups controlled by the purchasers of the nodes. Requests for access to these nodes will need to be confirmed by the owner of the node before access will be granted. We additionally have a node called burst1 used for lab and training sessions, and as a burst node for extending the capacity of the cluster outside term-time.

Restricted Access Required variables Count Cores RAM Accessible RAM Arch
ddy 68 48 384GB ~362GB Intel
nxv 8 32 256GB ~236GB Intel
sbg (ampere) gpu 2 48 384GB ~362GB Intel
sbg (ampere) gpu, cluster=andrena 16 48 384GB ~362GB Intel
sdv serial 10 24 192GB ~177GB Intel
sdv parallel infiniband=sdv-ii 15 24 192GB ~177GB Intel
srm highmem 1 48 1536GB ~1483GB Intel
panos1 1 32 512GB ~491GB Intel
burst1 1 40 768GB ~741GB Intel
Total 122 5104 42.7TB

Owned nodes complex

Users with access to owned nodes can ensure jobs run on an owned node by requesting -l owned in the job script or on the command line e.g. qlogin -l owned

The following table lists the CPU instruction sets supported by Apocrita Nodes. Note that AVX-512 is a family of extensions and an entry in this table may not mean that all AVX-512 extensions are supported on the node. To see whether a particular AVX-512 extension is supported you can check the CPU flags on a specific node.

Node Type SSE SSE2 SSSE3 SSE4 AVX AVX2 AVX-512
ddy
emf
nxv
nxg
sdv
srm
sbg
sdx

Hyperthreading is not enabled on compute nodes. Jobs are therefore allocated real cores.