PantheonSim / GPUs / NVIDIA A100-SXM4-80GB
Simulated NVIDIA A100-SXM4-80GB: a GPU profile for CUDA and ROCm testing
PantheonSim, the GPU simulator for CUDA and ROCm, simulates the NVIDIA A100-SXM4-80GB (Ampere, 8.0) as the profile nvidia/a100.
The A100 as an SXM4 module with 80 GB of HBM2e, the Ampere data-center part used on NVLink-connected multi-GPU baseboards. Its profile is verified, which means it was read from a physical card.
The profile at a glance
These are the numbers a program can ask this simulated GPU, and the values nvidia-smi show for it. They come from the profile file in the simulator's repository, pinned to one commit of it.
| Property | Value |
|---|---|
| Profile id | nvidia/a100 |
| Vendor and architecture | NVIDIA, Ampere |
| Compute capability | 8.0 |
| Device memory | 79.3 GiB, HBM |
| Streaming multiprocessors | 108 |
| Warp size | 32 |
| Max threads per multiprocessor | 2048 |
| Shared memory per block (opt-in maximum) | 163 KiB |
| L2 cache | 40 MiB |
| Memory bus width | 5120-bit |
| Power limit (profile) | 400 W |
| Maximum clocks (profile) | 1410 MHz shader, 1593 MHz memory |
| ECC memory | yes |
| PCIe link reported | Gen4 x16 |
| NVLink reported | NVLink3 x12 |
| Tensor or matrix cores | yes |
| Verified (measured on a physical card) | yes |
What this GPU is for
The A100 as an SXM4 module with 80 GB of HBM2e, the Ampere data-center part used on NVLink-connected multi-GPU baseboards.
Ampere covers two compute capabilities in these profiles: 8.0 for the GA100 data-center parts and 8.6 for the GA10x parts. The simulator runs the SASS a binary carries for the architecture and falls back to PTX when it carries none.
Among the 37 NVIDIA profiles it ranks 15th by device memory (79.3 GiB) and 19th by SMs (108), counting the largest as first.
Is this profile verified?
Yes. This profile is marked verified, which means its values were read from a physical NVIDIA A100-SXM4-80GB by the simulator's characterization tools, not copied from a data sheet. Verified describes the profile's numbers: it says nothing about speed, because the simulator has no timing model.
Simulate this GPU
Build the simulator (see the docs) or open the playground, then:
nvcc -cudart shared -arch=compute_80 my_app.cu -o my_app vgpu run --gpu nvidia/a100 ./my_app vgpu shell -y --gpu nvidia/a100 --count 4 vgpu info --gpu nvidia/a100
This profile is compute capability 8.0. A kernel built for compute_75 runs on it and on every other NVIDIA profile; a kernel built for a newer architecture is refused by a profile that is older than it. Link the CUDA runtime shared (-cudart shared) so the simulator can stand in for it.
To use it every time, put gpu: nvidia/a100 in a pantheonsim.yaml settings file, or in a GitHub Actions job give the PantheonSim action gpu: nvidia/a100 (see CUDA and HIP tests in GitHub Actions). The simulator checks behaviour and has no timing model, so a run on a physical GPU before a release still counts. The CUDA guide explains the rest.
Where the numbers come from
Each profile file begins with a note on its sources. This is the note for NVIDIA A100-SXM4-80GB, as written in the file:
Source note for nvidia/a100
Read from a physical A100-SXM4-80GB on a Lambda 8x instance by nvidia/tools/characterize.cu. The residency ceilings are the sm_80 constants, which the 40 GB part reported identically.
The GPU index lists every profile, and this one is measured on a physical card.
Related GPUs
Other Ampere profiles: