diff --git a/extra/gemm/amd_uop_matmul.py b/extra/gemm/amd_uop_matmul.py
index 4944d75153..b7a8ed7aa5 100644
--- a/extra/gemm/amd_uop_matmul.py
+++ b/extra/gemm/amd_uop_matmul.py
@@ -8,17 +8,20 @@ N = 4096
 run_count = 5
 
 def hand_spec_kernel3():
-  BLOCK_SIZE = 256
-
+  # block tile size
   BN = 128
   BM = 128
+  # number of row/column we read per batch
   BK = 8
 
+  # thread tile size 4x4
   TN = 4
   TM = 4
 
+  BLOCK_SIZE = 128
   nbWaves = BLOCK_SIZE // 32
-  WN = 64
+  # wave tile size
+  WN = 128
   WM = BN * BM // nbWaves // WN
 
   nbWaveX = BN // WN
@@ -65,7 +68,7 @@ def hand_spec_kernel3():
   A_col = UOp(Ops.DEFINE_REG, dtypes.float.ptr(nbIterWaveM * TM, AddrSpace.REG), src=(junk,), arg=0)
   B_row = UOp(Ops.DEFINE_REG, dtypes.float.ptr(nbIterWaveN * TN, AddrSpace.REG), src=(junk,), arg=1)
 
-  As = UOp(Ops.DEFINE_LOCAL, dtypes.float.ptr(BK*BM, AddrSpace.LOCAL), arg=0)
+  As = UOp(Ops.DEFINE_LOCAL, dtypes.float.ptr(BK*(BM+4), AddrSpace.LOCAL), arg=0) # 4 padding to avoid bank conflicts
   Bs = UOp(Ops.DEFINE_LOCAL, dtypes.float.ptr(BK*BN, AddrSpace.LOCAL), arg=1)
 
   c_regs = UOp(Ops.DEFINE_REG, dtypes.float.ptr(TM * nbIterWaveM * TN * nbIterWaveN), src=(junk,), arg=2)
@@ -77,12 +80,12 @@ def hand_spec_kernel3():
   i = UOp.range(dtypes.int, nbReadsB, 1)
   index_x = BN * blockIdx_x + rBIdx
   index_y = rBIdy + i * strideReadB + kId
-  Bs_store = Bs[(index_y % BK) * BN + index_x % BN].store(b[N * index_y + index_x].load(), i)
+  Bs_store = Bs[(index_y % BK)*BN + index_x%BN].store(b[N * index_y + index_x].load(), i)
 
   i = UOp.range(dtypes.int, nbReadsA, 2)
   index_x = rAIdx + kId
   index_y = BM * blockIdx_y + rAIdy + i * strideReadA
-  As_store = As[(index_x % BK) * BM + index_y % BM].store(a[N * index_y + index_x].load(), i)
+  As_store = As[(index_x % BK)*(BM+4) + index_y%BM].store(a[N * index_y + index_x].load(), i)
 
   barrier = UOp(Ops.BARRIER, src=(As_store, Bs_store))
 
@@ -97,7 +100,7 @@ def hand_spec_kernel3():
   iterWave = UOp.range(dtypes.int, nbIterWaveM, 6)
   i = UOp.range(dtypes.int, TM, 7)
   index = waveIdy * WM + iterWave * SUBWM + TM * idyInWave + i
-  A_col_store = A_col[iterWave*TM + i].store(As[k*BM + index].load(barrier), iterWave, i)
+  A_col_store = A_col[iterWave*TM + i].store(As[k*(BM+4) + index].load(barrier), iterWave, i)
 
   # do the GEMM math
   iterWaveM = UOp.range(dtypes.int, nbIterWaveM, 8)