Fox

Picture by Joanne Redwood, CC0.

The fox machine is a big GPU server that is configured to run heavy workloads. It has two fast AMD CPUs with large cache and 2 reasonable NVIDIA GPUs. Here are the detailed specifications:

Access

To access the machine, request a SLURM session from apex using the fox partition and set the time for the reservation (the default is 1 hour). If you need the machine for performance measurements, use an exclusive reservation:

apex% salloc -p fox -t 02:00:00 --exclusive
fox%

Otherwise, specify the CPUs that you need so other users can also use the node at the same time:

apex% salloc -p fox -t 02:00:00 -c 8
fox%

Make sure you get all CPUs you expect:

fox% grep Cpus_allowed_list /proc/self/status
Cpus_allowed_list:	0-191

Follow these steps if you don’t have access to apex or fox.

CUDA

To use CUDA you’ll need to load the NVIDIA nvcc compiler and some additional libraries in the environment. Clone the following example and modify the flake.nix if needed to add additional packages.

Then just run nix develop from the same directory to spawn a new shell with the CUDA environment:

fox% git clone https://jungle.bsc.es/git/rarias/devshell

fox% cd devshell/cuda

fox% nix develop

fox$ nvcc -V
nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2025 NVIDIA Corporation
Built on Fri_Feb_21_20:23:50_PST_2025
Cuda compilation tools, release 12.8, V12.8.93
Build cuda_12.8.r12.8/compiler.35583870_0

fox$ make
nvcc -ccbin g++ -m64 -Wno-deprecated-gpu-targets -o cudainfo cudainfo.cpp

fox$ ./cudainfo
./cudainfo Starting...

 CUDA Device Query (Runtime API) version (CUDART static linking)

Detected 2 CUDA Capable device(s)
...

AMD uProf

The AMD uProf performance analysis tool-suite is installed and ready to use.

See the AMD uProf user guide (PDF backup for v5.1) for more details on how to use the tools. To use the GUI make sure that you connect to fox using X11 forwarding.

Filesystems

The machine has several file systems available.