# MIG Instances Utilization Calculation

**URL:** <https://forums.developer.nvidia.com/t/mig-instances-utilization-calculation/341194>\
**Category:** General Discussion\
**Tags:** cuda, kernel\
**Created:** [August 4, 2025, 12:16pm UTC](https://forums.developer.nvidia.com/t/mig-instances-utilization-calculation/341194 "2025-08-04T12:16:40Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![sabavath.n](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@sabavath.n](https://forums.developer.nvidia.com/u/sabavath.n)\
**Post date:** [August 4, 2025, 12:16pm UTC](https://forums.developer.nvidia.com/t/mig-instances-utilization-calculation/341194/1 "2025-08-04T12:16:40Z")

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Hi

I’ve configured a Kubernetes cluster on a MIG-enabled GPU node and partitioned the GPU into 4 distinct MIG instances, each with a different slice configuration (2g.20gb, 1g.10gb, 3g.40gb, 1g.10gb).

System Details :  
Driver Version: 555.42.06  
CUDA Version: 12.5  
GPU: NVIDIA H100 80GB HBM3

| MIG Device | Slice Type | SMs | Memory |
| --- | --- | --- | --- |
| GPU-I 3 | 3g.40gb | 60 | 40 GB |
| GPU-I 2 | 2g.20gb | 32 | 20 GB |
| GPU-I 0 | 1g.10gb | 16 | 10 GB |
| GPU-I 1 | 1g.10gb | 16 | 10 GB |

I used the following **DCGM command** to collect GPU utilization metrics

dcgmi dmon -e 1001,1004 -g 2

i got

# Entity GRACT TENSO

GPU 0 0.422 0.876  
GPU-I 3 0.984 0.816 # 3g.40gb  
GPU-I 2 0.989 0.913 # 2g.20gb  
GPU-I 0 0.995 0.965 # 1g.10gb  
GPU-I 1 0.995 0.964 # 1g.10gb

According to the documentation ( [Feature Overview — NVIDIA DCGM Documentation latest documentation](https://docs.nvidia.com/datacenter/dcgm/latest/user-guide/feature-overview.html#profiling-metrics) )

the formula above with our actual usage values results in a **GPU 0 GRACT value** that **does not match** the value reported by DCGM (`0.422`). This discrepancy appears when MIG instances are of **different slice types** , unlike the examples given in the documentation which use identical slices.

### Questions:

1. **What is the correct method to calculate the overall GPU utilization (`GRACT`, `TENSO`) when MIG instances are heterogeneous (e.g., 3g, 2g, 1g)?** Please provide a formula or working example for mixed-slice setups.
2. **Why does the `GPU 0` GRACT not match the sum of weighted instance utilizations in our case?**  
Are there any internal weights or normalization factors beyond SM count?
3. **Is `dcgmi dmon` the only officially supported way to monitor per-slice and full GPU utilization?**  
Do other tools like **DCGM APIs** , **NVML** , or **NVIDIA NSIGHT** offer more accurate or detailed slice-level telemetry?

We would highly appreciate any clarification or documentation references on these topics. This would help us accurately monitor GPU workloads in production Kubernetes environments using MIG