Over the past week, I’ve been building gb10-kernel-probe to address a gap in GB10 / SM121a characterization tooling.
The tool runs sustained CUTLASS GEMM sweeps across tile and cluster-topology configurations while collecting hardware telemetry throughout execution.
Current sweep axes include:
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threadblock tile shape
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warp tile shape
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pipeline stage depth
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cluster topology
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datatype
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alignment
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matrix layout
Telemetry captured per config includes:
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TFLOPS
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shared memory usage
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occupancy
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GPU temperature
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power draw
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SM clocks
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PTX/kernel metadata
The sweep data is now exposing scheduling, thermal, power, and topology behavior during sustained tensor-core GEMM execution on GB10 systems.
New comparison data from two GB10 platforms:
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ASUS GX10 (azampatti)
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DGX Spark (dustin1925)
Important context:
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azampatti ran the 48-config fast sweep
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dustin1925 ran the full 96-config sweep (
--full, all cluster shapes enabled)
=== STARTING CONDITIONS ===
azampatti (GX10):
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Start temp: 56°C
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Warm-start condition
dustin1925 (DGX Spark):
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Start temp: 42°C
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Cool-start condition
Despite the 14°C difference at sweep start, both systems converged near the same sustained operating region during tensor-core GEMM execution.
=== THERMAL BEHAVIOR ===
azampatti (GX10):
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Rapid thermal rise
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Plateau behavior near ~62°C
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~+6°C rise during 48-config sweep
dustin1925 (DGX Spark):
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Gradual thermal accumulation
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Stabilized near ~62-65°C
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~+20°C rise during full 96-config sweep
=== POWER / CLOCK BEHAVIOR ===
GX10:
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Avg Power: ~68.4 W
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Peak Power: ~76.9 W
DGX Spark:
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Avg Power: ~67.7 W
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Peak Power: ~81.4 W
Both systems maintained stable sustained power behavior throughout execution.
=== PERFORMANCE OBSERVATIONS ===
No sustained thermal or clock throttling was observed on either system.
One interesting result:
the highest throughput configuration did NOT correspond to the highest SM clocks.
Best config:
- 13.35 TFLOPS @ 2294 MHz
Lowest config:
- 3.97 TFLOPS @ 2398 MHz
For these GEMM kernels on GB10 / SM121a, tile shape, cluster topology, and occupancy behavior appear more influential than raw SM frequency alone.
=== CLUSTER TOPOLOGY RESULTS ===
64x64x32:
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1x1x1: 4.05 TFLOPS
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2x1x1: 3.99 TFLOPS
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2x2x1: 3.97 TFLOPS
The smaller tile regresses slightly as cluster size increases.
128x128x32:
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1x1x1: 13.20 TFLOPS
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2x1x1: 13.35 TFLOPS
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2x2x1: 13.10 TFLOPS
The larger tile benefits modestly from 2x1x1, then regresses again at 2x2x1.
So larger cluster topology is not acting as a universal throughput gain on GB10:
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smaller tiles regress slightly
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larger tiles benefit modestly from 2x1x1
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larger cluster grouping does not consistently improve throughput
The analyzer layer is now exposing:
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thermal trajectory
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sustained power behavior
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topology sensitivity
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clock stability
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platform convergence behavior
rather than raw benchmark numbers alone.
Huge thanks to:
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azampatti for the GX10 sweep data
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dustin1925 for the full sustained DGX Spark runs and validation work
Community-contributed runs are making it possible to build real comparative SM121a characterization data instead of isolated single-system observations.
Tooling + methodology:
https://github.com/parallelArchitect/gb10-kernel-probe