SXM (Server PCI Express Module) is a proprietary GPU socket form factor used in NVIDIA's high-end datacenter products (H100 SXM, A100 SXM, B200 SXM). Unlike PCIe cards, SXM modules plug into a dedicated baseboard that supports higher TDP, denser packaging, and NVLink connectivity between modules.
A typical SXM baseboard hosts 4 or 8 GPUs (HGX form factor) connected to each other through NVLink Switch chips, enabling the full inter-GPU bandwidth that distributed training requires. This makes SXM the standard form factor for clusters running large-model training.
SXM variants typically cost more per GPU-hour to rent than their PCIe counterparts because of the additional infrastructure (baseboard, NVLink, higher cooling capacity). AIMC tracks SXM and PCIe variants as separate canonical SKUs.