diff --git a/av1/encoder/block.h b/av1/encoder/block.h
index 673192e..5094f3a 100644
--- a/av1/encoder/block.h
+++ b/av1/encoder/block.h
@@ -894,6 +894,9 @@
    */
   int rdmult;
 
+  // Intra only, per sb rd adjustment.
+  int intra_sb_rdmult_modifier;
+
   //! Superblock level distortion propagation factor.
   double rb;
 
diff --git a/av1/encoder/encodeframe.c b/av1/encoder/encodeframe.c
index 3f0a76d..990c201 100644
--- a/av1/encoder/encodeframe.c
+++ b/av1/encoder/encodeframe.c
@@ -600,6 +600,10 @@
   (void)gather_tpl_data;
 #endif
 
+  if (cpi->oxcf.mode == ALLINTRA) {
+    x->intra_sb_rdmult_modifier = 128;
+  }
+
   reset_mb_rd_record(x->txfm_search_info.mb_rd_record);
   av1_zero(x->picked_ref_frames_mask);
   av1_invalid_rd_stats(rd_cost);
diff --git a/av1/encoder/partition_search.c b/av1/encoder/partition_search.c
index 95341e0..45458c9 100644
--- a/av1/encoder/partition_search.c
+++ b/av1/encoder/partition_search.c
@@ -624,6 +624,9 @@
     av1_set_butteraugli_rdmult(cpi, x, bsize, mi_row, mi_col, &x->rdmult);
   }
 #endif
+  if (cpi->oxcf.mode == ALLINTRA) {
+    x->rdmult = (x->rdmult * x->intra_sb_rdmult_modifier) >> 7;
+  }
 }
 
 void av1_set_offsets_without_segment_id(const AV1_COMP *const cpi,
@@ -4773,6 +4776,22 @@
   // Set buffers and offsets.
   av1_set_offsets(cpi, tile_info, x, mi_row, mi_col, bsize);
 
+  if (cpi->oxcf.mode == ALLINTRA) {
+    if (bsize == cm->seq_params->sb_size) {
+      double var_min, var_max;
+      log_sub_block_var(cpi, x, bsize, &var_min, &var_max);
+
+      x->intra_sb_rdmult_modifier = 128;
+      if ((var_min < 2.0) && (var_max > 4.0)) {
+        if ((var_max - var_min) > 8.0) {
+          x->intra_sb_rdmult_modifier -= 48;
+        } else {
+          x->intra_sb_rdmult_modifier -= (int)((var_max - var_min) * 6);
+        }
+      }
+    }
+  }
+
   // Save rdmult before it might be changed, so it can be restored later.
   const int orig_rdmult = x->rdmult;
   setup_block_rdmult(cpi, x, mi_row, mi_col, bsize, NO_AQ, NULL);