fix(gptfast): align the implementation and config of Aria HF version

gptfast/model.py

@@ -45,7 +45,7 @@ class ModelArgs:
     intermediate_size: int = 1664
     n_local_heads: int = -1
     head_dim: int = 64
-    rope_base: float = 10000
+    rope_base: float = 5000000
     norm_eps: float = 1e-5
     use_scaled_rope: bool = False
     num_experts: int = 64
@@ -357,11 +357,10 @@ def forward(self, x: Tensor) -> Tensor:
         # T = num_tokens, E = num_experts, D = hidden dim, A = activated experts
         # x: [T, D]
         scores = self.gate(x)  # [T, E]
-        expert_weights = F.softmax(scores, dim=-1)
         expert_weights, expert_indices = torch.topk(
-            expert_weights, self.num_activated_experts, dim=-1
+            scores, self.num_activated_experts, dim=-1
         )  # [T, A], [T, A]
-        expert_weights /= expert_weights.sum(dim=-1, keepdim=True)  # [T, A]
+        expert_weights = F.softmax(expert_weights, dim=-1)
         expert_outs = self.cond_ffn(x, expert_indices, expert_weights)
         shared_outs = self.shared_ffn(x)
         return expert_outs + shared_outs