diff --git a/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py b/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py
index 64516ff..db5fa2f 100644
--- a/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py
+++ b/vllm_kunlun/v1/sample/ops/topk_topp_sampler.py
@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 from typing import Optional
-
+import os
 import torch
 import torch.nn as nn
 from packaging import version
@@ -150,7 +150,12 @@ def random_sample(
     # not have its own seed. Then, we overwrite the values for the requests
     # that have their own seeds.
     if len(generators) != probs.shape[0]:
-        q.exponential_()
+        if os.getenv('FAST_RANDOM_SAMPLE') == "1":
+            q.uniform_()
+            q = -torch.log(q)
+            q = q.clamp(min=1e-4)
+        else:
+            q.exponential_()
     if generators:
         # TODO(woosuk): This can be slow because we handle each request
         # one by one. Optimize this.