Hardware Environment
Technical Specifications
The IBM Power System compute nodes have the following technical characteristics:
| Commercial Name | S822LC 8335-GTB | AC922 8335-GTX 18-Cores | AC922 8335-GTX 22-Cores |
|---|---|---|---|
| # Sockets | 2 | 2 | 2 |
| CPU Model | POWER8NV | POWER9 | POWER9 |
| Physical Cores | 20 (2x10) | 36 (2x18) | 44 (2x22) |
| Hardware Threads (Per Physical Core) | 1 / 2 / 4 / 8 | 1 / 2 / 4 | 1 / 2 / 4 |
| Clock Frequency: Nominal / Max. (Turbo) | 2.86 GHz / 4.03 GHz | 3.15 GHz / 3.45 GHz | 2.80 GHz / 3.10 GHz |
| CPU Peak Performance (Double Precision) | 458 GFlops | 907 GFlops | 986 GFlops |
| L3 Cache (Per Physical Core) | 8 MB | 5 MB | 5 MB |
| L4 Cache | 16 MB per Buffer Chip | - | - |
| Memory Max. | 1 TB | 2 TB | 2 TB |
| Memory Bandwidth | 230 GB/s | 280 GB/s | 280 GB/s |
| # GPU Devices | 4 | 6 | 6 |
| GPU Model | NVIDIA Tesla P100 | NVIDIA Tesla V100 | NVIDIA Tesla V100 |
| GPU Peak Performance (Double Precision) | 5.3 TFlops | 7.8 TFlops | 7.8 TFlops |
| GPU Memory | 16 GB | 16 GB | 16 GB |
| GPU Memory Bandwidth | 732 GB/s | 900 GB/s | 900 GB/s |
| Node Peak Performance (Double Precision) | 22 TFlops | 48 TFlops | 48 TFlops |
Simultaneous Multi-Threading (SMT)
The IBM Power System nodes can be configured in distinct SMT modes.
Each SMT mode defines the number of logical cores (hardware threads) available on the node:
| SMT Mode | # Logical Cores |
|---|---|
| 1 (Off) | 20 |
| 2 | 40 |
| 4 | 80 |
| 8 | 160 |
SMT mode configuration does not require the system to be restarted; therefore, SMT mode configuration can be performed on-the-fly.