diff --git a/util/grand/grand_buffer.go b/util/grand/grand_buffer.go
index 2d108e4f7..f2b994e46 100644
--- a/util/grand/grand_buffer.go
+++ b/util/grand/grand_buffer.go
@@ -39,7 +39,8 @@ func asyncProducingRandomBufferBytesLoop() {
 			// so fully reuse the random buffer by changing
 			// the step with a different number can
 			// improve the performance a lot.
-			for _, step = range []int{4, 5, 6, 7} {
+			// for _, step = range []int{4, 5, 6, 7} {
+			for _, step = range []int{4} {
 				for i := 0; i <= n-4; i += step {
 					bufferChan <- buffer[i : i+4]
 				}