lower test_gemm_8192 amd to 70 (tinygrad#9277)

flaky

Author: chenyuxyz

test/external/speed_v_theoretical.py

@@ -91,7 +91,7 @@ def test_conv_3x3_256_32_32_256_256(self): self._test_conv_3x3(256, 32, 32, 256,
 
   # theoretical is nv_tflops=165, amd_tflops=123
   def test_gemm_4096(self): self._test_matmul(4096, nv_tflops=115, amd_tflops=80)
-  def test_gemm_8192(self): self._test_matmul(8192, nv_tflops=125, amd_tflops=73)
+  def test_gemm_8192(self): self._test_matmul(8192, nv_tflops=125, amd_tflops=70)
 
   # theoretical is nv_gbs=1008, amd_gbs=960
   def test_gemv_16384_4096(self): self._test_matmul(16384, 4096, 1, nv_gbs=840, amd_gbs=750)