diff --git a/lib/simd/Grid_gpu_vec.h b/lib/simd/Grid_gpu_vec.h
index 0d30c68d..471fbccc 100644
--- a/lib/simd/Grid_gpu_vec.h
+++ b/lib/simd/Grid_gpu_vec.h
@@ -36,9 +36,7 @@ Author: Peter Boyle <paboyle@ph.ed.ac.uk>
 
 namespace Grid {
 
-  //#define COALESCE_GRANULARITY (64) // bytes for coalesce granularity of target: Pascal, Volta
-  //#define COALESCE_GRANULARITY (32) // bytes for coalesce granularity of target: Pascal, Volta
-  #define COALESCE_GRANULARITY (16) // bytes for coalesce granularity of target: Pascal, Volta
+#define COALESCE_GRANULARITY ( GEN_SIMD_WIDTH )
 
 template<class pair>
 class GpuComplex {