diff --git a/comfy/ldm/modules/attention.py b/comfy/ldm/modules/attention.py
index 4eda361..f8391e1 100644
--- a/comfy/ldm/modules/attention.py
+++ b/comfy/ldm/modules/attention.py
@@ -124,11 +124,14 @@ def attention_basic(q, k, v, heads, mask=None):
 
 
 def attention_sub_quad(query, key, value, heads, mask=None):
-    scale = (query.shape[-1] // heads) ** -0.5
-    query = query.unflatten(-1, (heads, -1)).transpose(1,2).flatten(end_dim=1)
-    key_t = key.transpose(1,2).unflatten(1, (heads, -1)).flatten(end_dim=1)
-    del key
-    value = value.unflatten(-1, (heads, -1)).transpose(1,2).flatten(end_dim=1)
+    b, _, dim_head = query.shape
+    dim_head //= heads
+
+    scale = dim_head ** -0.5
+    query = query.unsqueeze(3).reshape(b, -1, heads, dim_head).permute(0, 2, 1, 3).reshape(b * heads, -1, dim_head)
+    value = value.unsqueeze(3).reshape(b, -1, heads, dim_head).permute(0, 2, 1, 3).reshape(b * heads, -1, dim_head)
+
+    key = key.unsqueeze(3).reshape(b, -1, heads, dim_head).permute(0, 2, 3, 1).reshape(b * heads, dim_head, -1)
 
     dtype = query.dtype
     upcast_attention = _ATTN_PRECISION =="fp32" and query.dtype != torch.float32
@@ -137,7 +140,7 @@ def attention_sub_quad(query, key, value, heads, mask=None):
     else:
         bytes_per_token = torch.finfo(query.dtype).bits//8
     batch_x_heads, q_tokens, _ = query.shape
-    _, _, k_tokens = key_t.shape
+    _, _, k_tokens = key.shape
     qk_matmul_size_bytes = batch_x_heads * bytes_per_token * q_tokens * k_tokens
 
     mem_free_total, mem_free_torch = model_management.get_free_memory(query.device, True)
@@ -171,7 +174,7 @@ def attention_sub_quad(query, key, value, heads, mask=None):
 
     hidden_states = efficient_dot_product_attention(
         query,
-        key_t,
+        key,
         value,
         query_chunk_size=query_chunk_size,
         kv_chunk_size=kv_chunk_size,
@@ -186,9 +189,19 @@ def attention_sub_quad(query, key, value, heads, mask=None):
     return hidden_states
 
 def attention_split(q, k, v, heads, mask=None):
-    scale = (q.shape[-1] // heads) ** -0.5
+    b, _, dim_head = q.shape
+    dim_head //= heads
+    scale = dim_head ** -0.5
+
     h = heads
-    q, k, v = map(lambda t: rearrange(t, 'b n (h d) -> (b h) n d', h=h), (q, k, v))
+    q, k, v = map(
+        lambda t: t.unsqueeze(3)
+        .reshape(b, -1, heads, dim_head)
+        .permute(0, 2, 1, 3)
+        .reshape(b * heads, -1, dim_head)
+        .contiguous(),
+        (q, k, v),
+    )
 
     r1 = torch.zeros(q.shape[0], q.shape[1], v.shape[2], device=q.device, dtype=q.dtype)
 
@@ -248,9 +261,13 @@ def attention_split(q, k, v, heads, mask=None):
 
     del q, k, v
 
-    r2 = rearrange(r1, '(b h) n d -> b n (h d)', h=h)
-    del r1
-    return r2
+    r1 = (
+        r1.unsqueeze(0)
+        .reshape(b, heads, -1, dim_head)
+        .permute(0, 2, 1, 3)
+        .reshape(b, -1, heads * dim_head)
+    )
+    return r1
 
 def attention_xformers(q, k, v, heads, mask=None):
     b, _, dim_head = q.shape