diff --git a/extra/gemm/asm/cdna/gemm.py b/extra/gemm/asm/cdna/gemm.py
index 1201966715..49b51f3fca 100644
--- a/extra/gemm/asm/cdna/gemm.py
+++ b/extra/gemm/asm/cdna/gemm.py
@@ -86,7 +86,7 @@ def asm_gemm(a:Tensor, b:Tensor) -> Tensor:
     out = Tensor.empty(batch, M, N, dtype=a.dtype, device=a.device)
 
   dname = a.device[0] if is_multi else a.device
-  arch = getattr(Device[dname].renderer, "arch", None)
+  arch = getattr(Device[dname].renderer, "arch", "")
   if arch.startswith("gfx950") and getenv("USE_ASM", 1):
     numWG = GEMM_ARGS[(M, N, K)][0]
     out = Tensor.custom_kernel(out, a, b, fxn=functools.partial(custom_asm_gemm, dname=dname, wg=numWG, arch=arch), grad_fxn=custom_gemm_bw)[0]
diff --git a/extra/gemm/asm/cdna/test_asm_gemm.py b/extra/gemm/asm/cdna/test_asm_gemm.py
index 905492cc60..8281446353 100644
--- a/extra/gemm/asm/cdna/test_asm_gemm.py
+++ b/extra/gemm/asm/cdna/test_asm_gemm.py
@@ -3,14 +3,14 @@ from tinygrad import Tensor, Device, dtypes, Context
 from tinygrad.helpers import getenv
 from extra.gemm.asm.cdna.gemm import asm_gemm
 
-def verify_asm_gemm(batch:int, M:int, N:int, K:int, dtype=dtypes.bfloat16, multi=False) -> None:
+def verify_asm_gemm(batch:int, M:int, N:int, K:int, dtype=dtypes.bfloat16, gpus:int=1) -> None:
   Tensor.manual_seed(0)
   a_rand = Tensor.randn((batch, M, K), dtype=dtypes.float).sub(0.5).cast(dtype)
   b_rand = Tensor.randn((K, N), dtype=dtypes.float).sub(0.5).cast(dtype)
   with Context(DEBUG=0):
     Tensor.realize(a_rand, b_rand)
 
-  devs = tuple(f"{Device.DEFAULT}:{i}" for i in range(8)) if multi else None
+  devs = tuple(f"{Device.DEFAULT}:{i}" for i in range(gpus)) if (multi:=gpus>1) else None
 
   a, b = Tensor(a_rand.numpy(), requires_grad=True).cast(dtype), Tensor(b_rand.numpy(), requires_grad=True).cast(dtype)
   if multi: a, b = a.shard(devs, axis=0), b.shard(devs, axis=None)
@@ -31,16 +31,23 @@ def verify_asm_gemm(batch:int, M:int, N:int, K:int, dtype=dtypes.bfloat16, multi
 
 class TestGemm(unittest.TestCase):
   def test_simple(self): verify_asm_gemm(1, N:=getenv("N", 4096), N, N, dtype=dtypes.half)
-
-  def test_gemm1(self): verify_asm_gemm(8, 8192, 4096, 14336, multi=True)
-  def test_gemm2(self): verify_asm_gemm(8, 8192, 128256, 4096, multi=True)
-  def test_gemm3(self): verify_asm_gemm(8, 8192, 14336, 4096, multi=True)
-  def test_gemm4(self): verify_asm_gemm(8, 4096, 14336, 4096, multi=True)
-  def test_gemm5(self): verify_asm_gemm(8, 4096, 4096, 14336, multi=True)
-  def test_gemm6(self): verify_asm_gemm(16, 4096, 4096, 14336, multi=True)
+  def test_gemm(self): verify_asm_gemm(1, 8192, 4096, 14336)
+  def test_gemm_multi(self): verify_asm_gemm(2, 8192, 4096, 14336, gpus=2)
   def test_gemm_unsupported(self):
     with self.assertRaisesRegex(AssertionError, "shape not supported"):
-      verify_asm_gemm(8, 8192, 1024, 4096, multi=True)
+      verify_asm_gemm(8, 8192, 1024, 4096, gpus=8)
+
+class TestGemmLarge(unittest.TestCase):
+  def setUp(self):
+    if getattr(Device[Device.DEFAULT].renderer, "arch", "") != "gfx950":
+      self.skipTest("very slow on non mi350x")
+
+  def test_gemm1(self): verify_asm_gemm(8, 8192, 4096, 14336, gpus=8)
+  def test_gemm2(self): verify_asm_gemm(8, 8192, 128256, 4096, gpus=8)
+  def test_gemm3(self): verify_asm_gemm(8, 8192, 14336, 4096, gpus=8)
+  def test_gemm4(self): verify_asm_gemm(8, 4096, 14336, 4096, gpus=8)
+  def test_gemm5(self): verify_asm_gemm(8, 4096, 4096, 14336, gpus=8)
+  def test_gemm6(self): verify_asm_gemm(16, 4096, 4096, 14336, gpus=8)
 
 if __name__ == "__main__":
   unittest.main()