models / compare / nemotron-3-ultra-vs-glm-5
Nemotron 3 Ultra vs GLM-5
How Nemotron 3 Ultra (NVIDIA, June 2026) and GLM-5 (Z.ai (Zhipu AI), February 2026) are built, drawn on the same November 2026 blueprint. They make different choices on 8 of 27 components. Select a component in either diagram to find it in the table.
--- frontier-llm@2026-11+++ nemotron-3-ultra@2026-06+0~4−7
Nemotron 3 Ultra
NVIDIA, June 2026, 550B total, 55B active
--- frontier-llm@2026-11+++ glm-5@2026-02+0~3−5
GLM-5
Z.ai (Zhipu AI), February 2026, 744B total, 40B active
Component by component
Nemotron 3 Ultra and GLM-5 differ on 8 of 27 components.
| Blueprint component | Nemotron 3 Ultra | GLM-5 |
|---|---|---|
Single residual stream, one sublayer per layer108 pre-norm layers on one d = 8,192 residual stream; each layer is one mixer or one MoE, not an attention+FFN pair. | Single residual streamOne d = 6,144 residual stream with pre-norm sublayers; no hyper-connections in GLM-5 through GLM-5.3. | |
RMSNorm on MLA latents (no per-head QK-Norm)Queries and keys are normalized as compressed latents (2,048 and 512 dims) before up-projection, not per head. | ||
Mamba-2 selective state-space layers48 of the 60 mixer layers: SSD with 256 heads × 64 dims, state size 128, 8 B/C groups, causal conv of kernel 4. | ||
Global GQA attention without positional encoding12 layers of dense causal attention: 64 query heads share 2 KV heads (d_h = 128); no RoPE, QK-norm, gate or sink. | Same as the blueprintMLA in all 78 layers and the MTP layer, with 64 heads: 2,048-dim query latent, 512-dim KV latent plus a 64-dim rotary key (576 cached values per token per layer), q/k head dim 256 (192 + 64 rotary), v head dim 256. This is the MLA-256 variant: head dim raised from 192 to 256 with one-third fewer heads, keeping training FLOPs and parameters roughly constant while lowering decode compute. | |
Same as the blueprintDSA in every layer, not alternated with MLA: a lightning indexer (32 heads × 128 dims, ReLU scores with learned per-head weights) selects the top 2,048 tokens per query and MLA attends only to those. It was added after mid-training: 1,000 warm-up steps on 14 × 202,752-token sequences, then 20B tokens of sparse adaptation. The indexer is frozen in RL and uses a deterministic torch.topk. GLM-5.2 runs it in 21 of 78 layers. | ||
LatentMoE routed experts (ReLU², 2,048-dim latent)512 non-gated squared-ReLU experts of width 5,120 run in a 2,048-dim latent space; 22 active per token. | Same as the blueprint256 routed SwiGLU experts of intermediate size 2,048, top-8 active, in 75 MoE layers. The first 3 layers use a dense SwiGLU FFN of width 12,288 instead. The MTP layer is also an MoE layer. | |
Same as the blueprintMuon, following GLM-4.5, with Muon Split: the MLA up-projections W_UQ, W_UK and W_UV are split per head and each block is orthogonalized separately, which brought MLA level with GQA-8 in Z.ai's ablation. The distributed implementation all-gathers only each rank's own shards. LR peaks at 2e-4, decays to 4e-5 in pretraining, then 1e-5 in mid-training. | ||
Same as the blueprintPretrained on 20T tokens in NVFP4 (E2M1 with 16-element blocks, 2D weight scaling, Random Hadamard Transforms on wgrad inputs, stochastic rounding of gradients). The final 16 layers, Mamba output projections, latent projections, QKV/attention projections, MTP layers and embeddings stayed in higher precision. The train-loss gap to BF16 branches stayed below 0.4% on average. | INT4 QAT in SFT, FP8 rolloutsINT4 quantization-aware training during SFT with a bitwise-identical kernel; FP8 inference for RL rollouts and release. |