Designing an open-source budget 4x V100 SXM2 NVLink backplane — passive PCIe vs PEX8749?

A hardware developer is designing an open-source, budget 4x V100 SXM2 NVLink backplane, weighing passive PCIe versus a PEX8749 switch, and has sourced technical references from Benchoff Design's reverse-engineering of the SXM2 socket and a blog post on dual Tesla V100 eGPU setups.

Do you actually have a good source for info on the 1CATai developments? The best I’m aware of is this The Most Esoteric eGPU: Dual NVIDIA Tesla V100 64G for AI & LLM https://blog.rexyuan.com/2025/09/30/v100/ I gotchu Reverse Engineering the NVIDIA SXM2 Socket | Benchoff Design Portfolio https://bbenchoff.com/pages/SXM2PCIe.html . I actually already had this open.