[R740XD] correct nvme card for 12nvme backplane?

Hi,

No, the 0W0DNK NVMe expanders from your current 0FJH5T (24 NVMe + 8 SAS/SATA) backplane are not compatible with the 0P1MJ3 (12 NVMe + 12 SAS/SATA) backplane.

## Backplane Differences
The 0FJH5T backplane uses a multiplexer (MUX) setup wired specifically for two 0W0DNK cards to support 24 NVMe drives, sharing PCIe lanes across them (about 1.3 lanes per drive on average).  In contrast, the 0P1MJ3 supports up to 12 NVMe drives using three 0235NK (or equivalent) PCIe NVMe adapters, providing full 4 PCIe lanes per drive for better throughput on fewer drives.  Dell documentation and user configurations confirm these backplanes require distinct expander cards and cabling, with no cross-compatibility due to connector and MUX wiring differences. 

## Required Parts for 0P1MJ3
- **NVMe Expanders**: Use 0235NK (PCIe x16 dual-port NVMe adapters); install up to three (one per 4 NVMe drives) in available PCIe slots like Riser 3A (slot 8) first. 
- **Cabling**: Custom Mini-SAS HD cables (e.g., Dell 1PDFM or equivalents) to connect expanders to backplane ports. 
- **Slots**: Start with slots 12-23 for NVMe (left-to-right facing front); slots 0-11 remain SAS/SATA. 

Verify your riser config and iDRAC for exact slot mapping, as GPU/PCIe usage (like your prior Tesla P40 setups) may limit options.  Source official Dell service manuals or test in a low-risk setup, as backplane swaps often need matched kits. 

I would recommend that you contact our sales department for getting all corect parts for your spcific system.