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Inference & ServingMedium· Inference Optimization· Quantization· Memory Bandwidth

Why is INT8 inference faster than BF16 inference at bat...

At a batch size of 1, the primary bottleneck for LLM inference is the time taken to load weights from HBM, not the arithmetic throughput of the compute units. Because INT8 weights are half the size of BF16 weights, the GPU can load the same number of parameters in half the time. The higher arithmetic throughput of INT8 tensor cores is secondary here, as the compute units are already waiting for data from HBM; therefore, the reduction in weight-loading time is the dominant factor in speeding up per-token decode latency.

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