There are three different partitions (SLURM lingo for 'queues') inside the cluster that support gpu usage: The titan-Queues (titanshort/long) currently include hosts i0001-i0009, while the gpu-Queues (infogpu) include the hosts g0001-g0009 ¹⁾. The titan-hosts carry 4 GeForce GTX TITAN, hence a usage request up to cuda=4 can be selected (see below). In contrast the GeForce GTX 480 is installed on the gpu-hosts (for the gpushort/long queues). Finally, for the tesla-Queues (teslashort/long) 4 Tesla K20m cards are installed.

To use a GPU you have to explicitly reserve it as a resource in the submission script:

#!/bin/bash
# ... other SBATCH statements
#SBATCH --gres=gpu:<number>
#SBATCH -p <appropriate partition>

Number can be anything from 1-4 on our GPU nodes. In order to use more than 1 GPU the application needs to support using this much, of course.

In order to use multiples nodes, you have to request more than one node.