⚡ Performance and Efficiency Benchmarks

NVIDIA Nemotron-3.5-Bolt-E4B (nemotron-bolt:e4b) is a post-trained Gemma-4-E4B-it and runs on the same engine and kernels as gemma4-it:e4b, so it performs like it. This page reports the measurements for the Bolt package.

Note:

  • Results are based on FastFlowLM 1.0.10 plus the Nemotron Bolt changes (a local build), under FLM’s default NPU power mode (Performance). Newer versions may deliver improved performance.
  • The Gemma 4 E4B row is measured in the same session on the same build.

Test System:

AMD Ryzen™ AI MAX+ PRO 395 (Strix Halo) with 128 GB DRAM (HP ZBook Ultra G1a).


🚀 Decoding Speed (TPS, or Tokens per Second, starting @ different context lengths)

Model HW 1k 2k 4k 8k 16k 32k
Nemotron Bolt E4B NPU (FLM) 12.8 12.5 11.9 10.9 9.2 7.2
Gemma 4 E4B NPU (FLM) 12.8 12.5 11.9 10.9 9.3 7.2

Nemotron Bolt supports up to 64k tokens of context (the default is 32k).


🚀 Prefill Speed (TPS, or Tokens per Second, with different prompt lengths)

Model HW 1k 2k 4k 8k 16k 32k
Nemotron Bolt E4B NPU (FLM) 438 542 606 643 611 516
Gemma 4 E4B NPU (FLM) 439 546 609 644 612 516

🚀 Time to First Token (Seconds)

Model HW 1k 2k 4k 8k 16k 32k
Nemotron Bolt E4B NPU (FLM) 2.2 3.6 6.4 12.1 25.4 60.1

🎯 Accuracy

The weights are converted from NVIDIA’s Q4_K_M release (see the model card).

Task accuracy: GSM8K (thinking off, greedy)

Run Problems Nemotron Bolt E4B
FastFlowLM CI bench, XRT 50 94.0%
FastFlowLM CI bench, HRX 50 94.0%

A paired check against the BF16 model (first 100 GSM8K test problems, one prompt, up to 512 new tokens): the NPU build solves 87, the BF16 model solves 90 (difference −3.0 points, 95% confidence interval −8.9 to +2.9; 6 problems only BF16 solves, 3 only the NPU build). With 100 problems this cannot tell a small loss from none.

Closeness to the BF16 model

Teacher-forced over 6,317 positions of the BF16 model’s own answers to 53 prompts (CPU simulation of the quantized weights):

Weights Top-1 agreement with BF16 Mean KL(BF16 ‖ quantized)
NVIDIA Q4_K_M as released 94.7% 0.044
FastFlowLM package (Q4_K_M converted to Q4_1) 94.1% 0.054
BF16 quantized straight to Q4_1 92.9% 0.076

The simulation keeps the tied output head at 8 bits; on the NPU it is 4-bit (Q4_1), as for Gemma 4 E4B.