Oversubscription
Provisioning less network bandwidth than full non-blocking would require; 1:1 is non-blocking, 3:1 is oversubscribed.
Current numbers
31.6% combined VMS + 2:1 modeled savingSemiAnalysis Oct 2024 1,024-H100 model: 31.6% back-end saving from virtual modular switch plus 2:1 oversubscription vs NVIDIA reference
31.6% combined-design savingCombined layout and oversubscription saving in one training-cluster model
~31%Modeled back-end fabric saving: virtual-modular-switch layout plus 2:1 oversubscription vs NVIDIA's 1,024-H100 reference (SemiAnalysis, Oct 2024, single source)