PCIe slots and adapters
Understanding the technical rules for PCIe adapters helps you correctly install and configure PCIe adapters in the system.
PCIe slots supported for different models
| Server rear and front view | Supported types and slot location | 
|---|---|
|  | Riser 1 assembly 
 Riser 2 assembly 
 | 
|  | Riser 1 assembly 
 | 
|  | Riser 1 assembly 1 Slot 1: PCIe 5 (x16), full-height, half-length | 
|  | Riser 1 assembly 
 Riser 2 assembly 
 | 
|  | Riser 1 assembly 
 Riser 2 assembly 
 | 
|  | Riser 1 assembly 1 Slot 1: PCIe 5 (x16), full-height, half-length | 
|  | Riser 3 assembly 
 Riser 4 assembly 
 | 
PCIe adapter installation rules and order
When installing different types of PCIe adapters, refer to the following suggested installation priority:
| Installation priority | |||
|---|---|---|---|
| 1. OCP module | 2. RAID adapter | 3. HBA adapter | 4. GPU adapter | 
| 5. InfiniBand adapter | 6. Fibre adapter | 7. Network adapter | 8. Serial port (COM) bracket | 
| Adapter type | Recommended slot installation priority | PCIe adapters | 
|---|---|---|
| OCP module | 
 Maximum quantity supported: 2 | 
 
 | 
| Slot 6 Maximum quantity supported: 1 | 
 | |
| RAID adapter | 
 Maximum quantity supported: 1 | 
 | 
| CFF Maximum quantity supported: 1 | 
 | |
| HBA adapter | 
 Maximum quantity supported: 3 | 
 | 
| 
 Maximum quantity supported: 1 | 
 | |
| CFF Maximum quantity supported: 1 | 
 | |
| GPU adapter | Slot 1 > Slot 2 > Slot 3 Maximum quantity supported: 3 | 
 Note When Lenovo Compute Complex Neptune Core Module is installed, the GPU adapter cannot be installed. | 
| InfiniBand adapter | Slot 1 > Slot 2 > Slot 3 Maximum quantity supported: 3 | 
 | 
| Slot 1 > Slot 2 > Slot 3 Maximum quantity supported: 2 | 
 Note When adding the ConnectX-8 adapter and auxiliary cable for the first time, follow the instructions in to enable the Gen 5 x32 host connection. For routing of the auxiliary cable, see Internal cable routing. | |
| Fibre adapter | Slot 1 > Slot 2 > Slot 3 Maximum quantity supported: 3 | 
 | 
| Network adapter | Slot 1 > Slot 2 > Slot 3 Maximum quantity supported: 3 | 
 | 
| Slot 1 > Slot 3 Maximum quantity supported: 2 | 
 | |
| Serial port (COM) bracket | Slot 1 Maximum quantity supported: 1 | 
 | 
Server front configuration and riser assemblies
See this section to identify the correlations between the front configuration and riser assemblies.
| Server front configuration | Riser 3 assembly | Riser 4 assembly | 
|---|---|---|
| Figure 1. Two front PCIe slots  | Figure 2. LP riser bracket  Figure 3. Riser card  | Figure 4. FH riser bracket  Figure 5. Riser card  | 
Server rear configuration and riser assemblies
See this section to identify the correlations between the rear configuration and riser assemblies.
| Server rear configuration | Riser 1 assembly | Riser 2 assembly | 
|---|---|---|
| Figure 6. Three PCIe slots  | Figure 7. LP-FH riser bracket  Figure 9. BF riser card  | Figure 10. LP riser bracket  Figure 11. LP riser card  | 
| Figure 12. Two PCIe slots  | Figure 13. FH riser bracket 1  Figure 14. FH riser card  | Figure 15. FH riser bracket 2  Figure 16. FH riser card  | 
| Figure 17. Two PCIe slots  | Figure 18. LP-FH riser bracket  Figure 20. BF riser card  | Riser 2 assembly is not supported. | 
| Figure 21. Two PCIe slots  | Figure 22. FH riser bracket 3  Figure 23. FH riser card  | Figure 24. LP riser bracket  Figure 25. LP riser card  | 
| Figure 26. One PCIe slot  | Figure 27. FH riser bracket 3  Figure 28. FH riser card  | Riser 2 assembly is not supported. | 
| Figure 29. One PCIe slot  | Figure 30. FH riser bracket 3  Figure 31. FH riser card  | Riser 2 assembly is not supported. | 
- The illustrations of riser brackets and cards may look slightly different from the physical ones. 
- BF: “butterfly”, a riser card with slots on both sides. 
