From c8fcbd66eef0ab48d9fe7e4ee35c683a193af46b Mon Sep 17 00:00:00 2001
From: comfyanonymous <121283862+comfyanonymous@users.noreply.github.com>
Date: Wed, 4 Feb 2026 16:37:05 -0800
Subject: [PATCH] Try to fix ace text encoder slowness on some configs.
 (#12290)

---
 comfy/ops.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/comfy/ops.py b/comfy/ops.py
index 53c5e4dc3..0f4eca7c7 100644
--- a/comfy/ops.py
+++ b/comfy/ops.py
@@ -54,6 +54,8 @@ try:
             SDPA_BACKEND_PRIORITY.insert(0, SDPBackend.CUDNN_ATTENTION)
 
             def scaled_dot_product_attention(q, k, v, *args, **kwargs):
+                if q.nelement() < 1024 * 128:  # arbitrary number, for small inputs cudnn attention seems slower
+                    return torch.nn.functional.scaled_dot_product_attention(q, k, v, *args, **kwargs)
                 with sdpa_kernel(SDPA_BACKEND_PRIORITY, set_priority=True):
                     return torch.nn.functional.scaled_dot_product_attention(q, k, v, *args, **kwargs)
         else: