| Check | What this checks | Target | Where | Verdict | Measured | Impact and what to do | $/day at risk |
|---|
| Scale-up bandwidth: all-reduce inside one server | Scale-up: how fast the GPUs inside one server combine their results over their own links (NVLink or xGMI). Every multi-GPU step on a server waits on this. | ≥ 350 GB/s reference: 350 GB/s intra-node all-reduce bus bandwidth (nccl-tests, 8 GPUs, 512 MB) | 2 nodes | meets | 436-437 GB/s over 8 GPUs against a floor of 350 | Met. Nothing to do. | none at risk |
| All-reduce returns correct values | Whether the GPUs combined those results correctly. A wrong value here means training would silently go wrong. | 0 incorrect reduction results nccl-tests checks every result | 2 nodes | meets | nccl-tests verified every reduction result | Met. Nothing to do. | none at risk |
| Scale-out bandwidth: all-reduce across servers | How fast GPUs on different servers can combine their results over the network between servers. This is what a multi-node training job waits on. | ≥ 100 GB/s reference: 100 GB/s across nodes (nccl-tests bus bandwidth, 16 GPUs on 2 nodes) | 2 nodes | meets | 130 GB/s over 16 GPUs against a floor of 100 | Met. Nothing to do. | none at risk |
| Memory integrity | Whether any GPU's memory has thrown an error it could not correct since boot. The driver contains such errors and terminates the affected job; the count is the history of that happening. | 0 uncorrectable errors since boot reference: 0 since boot | 16 GPUs | meets | no uncorrectable errors, since boot or on record | Met. Nothing to do. | none at risk |
| GPUs fit for work | The share of GPUs that passed every check, against the share the contract promises. | ≥ 97% of GPUs with no failed check reference: 0.97 of GPUs with no failed check | fleet | meets | 16 of 16 (100.0%) with no failed check; target 97% | Met. Nothing to do. | none at risk |
| No hardware-fault messages in the accessible kernel log | Whether the readable part of the kernel log holds any message that public vendor or kernel documentation classes as a hardware fault: uncorrectable PCIe or memory errors, a device dropping off the bus, a GPU reset. Benign and application-level messages are counted but never fail this. The log covers whatever the ring buffer still held at read time. | 0 fault-class messages public kernel and vendor documentation, per signature | 2 nodes | meets | no fault-class signature present | Met. Nothing to do. | none at risk |
| PCIe links at full width | How many PCIe lanes connect each GPU to its host. Fewer than the card supports means data moves between CPU and GPU more slowly than it should. | the card's own maximum link width the card's own reported limit | 16 GPUs | meets | all at rated width | Met. Nothing to do. | none at risk |
| Scale-out bandwidth: RDMA write between servers (host memory) | Scale-out: how fast one server's network card can write straight into another server's memory over RDMA (host memory in this test; GPUDirect is not exercised), the east-west path every multi-server job depends on, against the port's speed. | ≥ 80% of the port rate reference: 0.8 of port rate: ib_write_bw over native InfiniBand reached 96% (385.8 of 400 Gb/s) on the sample cluster; 80% leaves room for a busy switch. | slurm-worker-slinky-0/mlx5_0->slurm-worker-slinky-1 | meets | 384.34 of 400 Gb/s (96%; floor 80%) | Met. Nothing to do. | none at risk |
| Communication exposed on the reference step | What share of that reference step was spent waiting for GPUs to exchange gradients rather than computing, with no overlap: a worst case. | ≤ 25% of the step reference: 0.25 of the un-overlapped reference step | 2 nodes | meets | 14.9%-15.3% against a ceiling of 25% | Met. Nothing to do. | none at risk |
| Reference-step utilisation (MFU) | How much of each GPU's rated compute a fixed reference training step actually achieved (model FLOP utilisation). A GPU that is throttled or misconfigured scores low. This is our step, not your workload. | ≥ 60% of the datasheet peak reference: 0.60 on the REFERENCE STEP (dense bf16 MLP, 1.07 B params, 8192 tokens per GPU) | 16 GPUs | meets | 68.6%-71.2% against a floor of 60% | Met. Nothing to do. | none at risk |
| GPU temperatures within limit | GPU temperature against the limit at which the card starts holding its clocks back. | ≤ 85 °C reference: 85 C, CARRIED OVER from the A100's 'GPU Max Operating Temp' | 16 GPUs | meets | all at or below 85 C | Met. Nothing to do. | none at risk |
| No hardware-fault Xid codes in the accessible kernel log | Whether the GPU driver has logged a code NVIDIA classes as a hardware fault (an Xid) in the part of the kernel log the tool could read. Most Xids are the application's, and are not counted here. | 0 hardware fault codes NVIDIA Xid documentation | 2 nodes | meets | no hardware-class Xid in the readable log | Met. Nothing to do. | none at risk |