DeepSeek-V3.2-Exp · Final RMSNorm

Final RMSNorm

learnedself.norm(h, residual)

Rescale each position’s features using their root mean square, then apply learned gain.

\begin{aligned}m_2(x)&=\frac{1}{d}\sum_{j=1}^d x_j^2\\y&=\gamma_{\mathrm{final}}\odot\frac{x}{\sqrt{m_2(x)+\varepsilon}}\\\varepsilon&=10^{-6}\end{aligned}

in: $x_{61}$ [B batch, T positions, 7168 d]
out: $z$ [B batch, T positions, 7168 d]
parameters: 7,168

Normalized in float32, multiplied by the gain in float32, then cast back to the input type (model.py 302–306). It first adds the last block’s feed-forward update h to the residual (907).

Parameters

7,168 parameters per instance.

Exact per-instance accounting
Component	Calculation	Parameters
Learned gain	$7{,}168$	7,168
Per-instance total		7,168

Each normalization instance owns its learned gain vector.

Derived from the configured feature width; checkpoint tensors have not been independently counted.

Codemodel.py 280–908

model.py 280–306

    def __init__(self, dim: int, eps: float = 1e-6):
        super().__init__()
        self.dim = dim
        self.eps = eps
        self.weight = nn.Parameter(torch.ones(dim, dtype=torch.float32))

    def forward(self, x: torch.Tensor, residual: Optional[torch.Tensor] = None):
        """
        Forward pass for RMSNorm.

        Args:
            x (torch.Tensor): Input tensor.

        Returns:
            torch.Tensor: Normalized tensor with the same shape as input.
        """
        dtype = x.dtype
        if residual is None:
            x = x.float()
            var = x.pow(2).mean(-1, keepdim=True)
            x = x * torch.rsqrt(var + self.eps)
            return (self.weight * x).to(dtype)
        else:
            x = residual = x.float() + residual.float()
            var = x.pow(2).mean(-1, keepdim=True)
            x = x * torch.rsqrt(var + self.eps)
            return (self.weight * x).to(dtype), residual.to(dtype)

model.py 880–887

        self.embed = ParallelEmbedding(args.vocab_size, args.dim)
        self.layers = torch.nn.ModuleList()
        for layer_id in range(args.n_layers):
            self.layers.append(Block(layer_id, args))
        self.norm = RMSNorm(args.dim)
        # lm_head in the checkpoint is stored in bf16, while the parameter here is stored in fp32 for easier computation of logits later.
        self.head = ColumnParallelLinear(args.dim, args.vocab_size, dtype=torch.float32)
        self.register_buffer("freqs_cis", precompute_freqs_cis(args), persistent=False)

model.py 901–908

        seqlen = tokens.size(1)
        freqs_cis = self.freqs_cis[start_pos:start_pos+seqlen]
        mask = torch.full((seqlen, seqlen), float("-inf"), device=tokens.device).triu_(1) if seqlen > 1 else None
        h, residual = self.embed(tokens), None
        for layer in self.layers:
            h, residual = layer(h, residual, start_pos, freqs_cis, mask)
        h, _ = self.norm(h, residual)
        logits = self.head(h[:, -1].float())

Sources2

Direct evidence

RMSNorm owns one gain per feature and computes in float32; with a residual argument it first adds the residual, fusing the residual addition into the next normalization.

rmsnorm · deepseek-ai/DeepSeek-V3.2-Exp / inference/model.py
Pinned revision 87e509a2e5a1 ↗ · lines 280–306

Read code excerpt

    def __init__(self, dim: int, eps: float = 1e-6):
        super().__init__()
        self.dim = dim
        self.eps = eps
        self.weight = nn.Parameter(torch.ones(dim, dtype=torch.float32))

    def forward(self, x: torch.Tensor, residual: Optional[torch.Tensor] = None):
        """
        Forward pass for RMSNorm.

        Args:
            x (torch.Tensor): Input tensor.

        Returns:
            torch.Tensor: Normalized tensor with the same shape as input.
        """
        dtype = x.dtype
        if residual is None:
            x = x.float()
            var = x.pow(2).mean(-1, keepdim=True)
            x = x * torch.rsqrt(var + self.eps)
            return (self.weight * x).to(dtype)
        else:
            x = residual = x.float() + residual.float()
            var = x.pow(2).mean(-1, keepdim=True)
            x = x * torch.rsqrt(var + self.eps)
            return (self.weight * x).to(dtype), residual.to(dtype)

Direct evidence

The model embeds tokens, applies all blocks with a causal mask, normalizes and projects to vocabulary logits with an untied head. The reference generator projects only the last position; training projects every position.

transformer · deepseek-ai/DeepSeek-V3.2-Exp / inference/model.py
Pinned revision 87e509a2e5a1 ↗ · lines 880–908

Read code excerpt

        self.embed = ParallelEmbedding(args.vocab_size, args.dim)
        self.layers = torch.nn.ModuleList()
        for layer_id in range(args.n_layers):
            self.layers.append(Block(layer_id, args))
        self.norm = RMSNorm(args.dim)
        # lm_head in the checkpoint is stored in bf16, while the parameter here is stored in fp32 for easier computation of logits later.
        self.head = ColumnParallelLinear(args.dim, args.vocab_size, dtype=torch.float32)
        self.register_buffer("freqs_cis", precompute_freqs_cis(args), persistent=False)

… lines 888–900 omitted …

        seqlen = tokens.size(1)
        freqs_cis = self.freqs_cis[start_pos:start_pos+seqlen]
        mask = torch.full((seqlen, seqlen), float("-inf"), device=tokens.device).triu_(1) if seqlen > 1 else None
        h, residual = self.embed(tokens), None
        for layer in self.layers:
            h, residual = layer(h, residual, start_pos, freqs_cis, mask)
        h, _ = self.norm(h, residual)
        logits = self.head(h[:, -1].float())