diff --git a/examples/mlperf/optim.py b/examples/mlperf/optim.py
index b6cc5ca193..4c6b4f5bc7 100644
--- a/examples/mlperf/optim.py
+++ b/examples/mlperf/optim.py
@@ -34,10 +34,10 @@ class GradAccClipAdamW(Optimizer):
       grads[0].assign((grads[0] * (self.clip_norm / (total_norm + 1e-6)).clamp(max_=1.0)).cast(grads[0].dtype))
     else:
       for i in range(len(grads)):
-        grads[i].assign(grads[i] / self.grad_acc).realize()
-      total_norm = Tensor.stack(*[g.float().square().sum() for g in grads]).sum().sqrt().contiguous().realize()
+        grads[i].assign(grads[i] / self.grad_acc)
+      total_norm = Tensor.stack(*[g.float().square().sum() for g in grads]).sum().sqrt().contiguous()
       for i in range(len(grads)):
-        grads[i].assign((grads[i] * (self.clip_norm / (total_norm + 1e-6)).clamp(max_=1.0)).cast(grads[i].dtype)).realize()
+        grads[i].assign((grads[i] * (self.clip_norm / (total_norm + 1e-6)).clamp(max_=1.0)).cast(grads[i].dtype))
 
     ret = []
     self.b1_t *= self.b1
@@ -45,8 +45,8 @@ class GradAccClipAdamW(Optimizer):
     for i, g in enumerate(grads):
       self.m[i].assign((self.b1 * self.m[i] + (1.0 - self.b1) * g).cast(self.m[i].dtype))
       self.v[i].assign((self.b2 * self.v[i] + (1.0 - self.b2) * (g * g)).cast(self.v[i].dtype))
-      m_hat = self.m[i] / (1.0 - self.b1_t)
-      v_hat = self.v[i] / (1.0 - self.b2_t)
+      m_hat = (self.m[i] / (1.0 - self.b1_t)).cast(self.m[i].dtype)
+      v_hat = (self.v[i] / (1.0 - self.b2_t)).cast(self.v[i].dtype)
       up = m_hat / (v_hat.sqrt() + self.eps)
       ret.append((self.lr * up).cast(g.dtype))
     return ret, [self.b1_t, self.b2_t] + self.m + self.v + [total_norm]