Glossary3 sections1 min read
What is NVSwitch?
NVSwitch is a switch chip that connects many GPUs over NVLink so that every GPU can talk to every other one at full NVLink speed, instead of only to its direct neighbors.
Why it matters when renting a GPU
In an 8-GPU server, all-to-all traffic (for example gradient exchange) would bottleneck on point-to-point links alone. NVSwitch removes that bottleneck.
When you rent a multi-GPU machine for training, ask whether the GPUs are SXM boards on an NVSwitch baseboard or separate PCIe cards.
Worked example
With NVSwitch, each H100 SXM in an 8-GPU server keeps its full NVLink 4 (900 GB/s) to the others, so the 8 GPUs pool 8 × 80 = 640 GB of HBM for one sharded model.
Frequently asked questions
- Is NVSwitch the same as NVLink?
- No. NVLink is the link; NVSwitch is the switch that connects many NVLinks so all GPUs reach each other at full speed.