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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 Arch
ddy 56 48 384GB Intel
emf highmem 14 24 768GB Intel
nxv 34 32 256GB Intel
nxg gpu 4 32 256GB Intel
sbg gpu 3 32 384GB Intel
sdv infiniband=sdv-i 32 24 192GB Intel
sdx 52 36 384GB Intel
srm highmem 2 36 768GB Intel
Total 197 7048 70.8TB

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 Arch
ddy 58 48 384GB Intel
nxn infiniband=nxn 32 16 64GB Intel
nxn 6 24 192GB Intel
nxv 8 32 256GB Intel
sdv serial 10 24 192GB Intel
sdv parallel infiniband=sdv-ii 15 24 192GB Intel
panos1 1 32 512GB Intel
burst1 1 40 768GB Intel
Total 131 4368 33.6TB

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
nxn parallel
nxn serial
nxv
nxg
sdv
srm
sbg
sdx

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