diff --git a/test/test_ops.py b/test/test_ops.py
index 1798f5f6..edac7ab6 100644
--- a/test/test_ops.py
+++ b/test/test_ops.py
@@ -4,7 +4,7 @@ import math
 import numpy as np
 import unittest
 from tinygrad.tensor import Tensor
-from tinygrad.helpers import getenv, IMAGE, DEBUG, CI, dtypes
+from tinygrad.helpers import getenv, IMAGE, DEBUG, CI, dtypes, Context, NOOPT
 from tinygrad.ops import Device
 
 if CI:
@@ -754,6 +754,11 @@ class TestOps(unittest.TestCase):
       lambda x,w: torch.nn.functional.conv2d(x,w).relu(),
       lambda x,w: Tensor.conv2d(x,w).relu(), atol=1e-4, grad_rtol=1e-5)
 
+  def test_simple_conv2d_noopt(self):
+    # useful with IMAGE enabled
+    with Context(NOOPT=1):
+      self.test_simple_conv2d()
+
   @unittest.skipIf(IMAGE>0, "no conv3d on images")
   def test_simple_conv3d(self):
     helper_test_op([(1,4,9,9,9), (4,4,3,3,3)],
diff --git a/tinygrad/helpers.py b/tinygrad/helpers.py
index aa5a0223..f6769919 100644
--- a/tinygrad/helpers.py
+++ b/tinygrad/helpers.py
@@ -60,7 +60,7 @@ class ContextVar:
   def __gt__(self, x): return self.value > x
   def __lt__(self, x): return self.value < x
 
-DEBUG, IMAGE, BEAM = ContextVar("DEBUG", 0), ContextVar("IMAGE", 0), ContextVar("BEAM", 0)
+DEBUG, IMAGE, BEAM, NOOPT = ContextVar("DEBUG", 0), ContextVar("IMAGE", 0), ContextVar("BEAM", 0), ContextVar("NOOPT", 0)
 GRAPH, GRAPHPATH = getenv("GRAPH", 0), getenv("GRAPHPATH", "/tmp/net")
 
 class Timing(contextlib.ContextDecorator):
diff --git a/tinygrad/ops.py b/tinygrad/ops.py
index 1e2575f6..b4d1f347 100644
--- a/tinygrad/ops.py
+++ b/tinygrad/ops.py
@@ -2,7 +2,7 @@ from __future__ import annotations
 import importlib, inspect, functools, pathlib, itertools, random, math, collections
 from enum import Enum, auto
 from typing import TYPE_CHECKING, Union, Type, Tuple, Any, List, Optional, Dict, Callable, Mapping
-from tinygrad.helpers import ansilen, prod, DEBUG, getenv, GlobalCounters, DType, colored, BEAM
+from tinygrad.helpers import ansilen, prod, DEBUG, getenv, GlobalCounters, DType, colored, BEAM, NOOPT
 from tinygrad.runtime.lib import RawBuffer
 from tinygrad.shape.symbolic import Variable, sym_infer
 from dataclasses import dataclass
@@ -312,7 +312,7 @@ class Compiled:
       from tinygrad.codegen.linearizer import Linearizer
       k = Linearizer(ast, self.linearizer_opts)
       assert k.info.dtype == output.dtype, f"linearizer must match dtype. linearizer wants {k.info.dtype} but buffer is {output.dtype}"
-      if not getenv("NOOPT"):
+      if not NOOPT:
         if not (used_tensor_cores:=k.apply_tensor_cores(getenv("TC", 1))): k.hand_coded_optimizations()
         if BEAM >= 1 and not vars_from_ast(ast):
           lins = [(("tc" if used_tensor_cores else "hc"), k)]
@@ -328,6 +328,8 @@ class Compiled:
           timed = sorted([(nm, tk, time_linearizer(tk, test_rawbuffers, allow_test_size=False, disable_cache=True, clear_l2=True)) for nm, tk in lins], key=lambda x: x[2])
           if DEBUG >= 1: print("  <  ".join(f"{nm:6s} : {lin.colored_shape(30, dense=True)} : {tm*1e6:8.2f} us" for nm, lin, tm in timed))
           k = timed[0][1]
+      else:
+        k.required_optimizations()
       return self.to_program(k)
 
     if getenv("ENABLE_METHOD_CACHE", 1):
diff --git a/tinygrad/renderer/cstyle.py b/tinygrad/renderer/cstyle.py
index 070a2644..9ac119b9 100644
--- a/tinygrad/renderer/cstyle.py
+++ b/tinygrad/renderer/cstyle.py
@@ -61,7 +61,7 @@ class CStyleLanguage(NamedTuple):
   # returns a str expression of the loaded value with the output type
   def render_load(self, output_dtype, buf_name, buf_dtype, idx, local=False) -> str:
     if isinstance(buf_dtype, ImageDType):
-      assert output_dtype == dtypes._float4, "images must be float4"
+      assert output_dtype == dtypes._float4, f"images must be float4, getting {output_dtype}"
       return f"read_imagef({buf_name}, smp, {idx})"
     if self.uses_vload and buf_dtype == dtypes.float16:
       return f"vload_half{'' if output_dtype.sz == 1 else str(output_dtype.sz)}(0, {buf_name}+{idx})"