diff --git a/scripts/dbgbmap.py b/scripts/dbgbmap.py
index 61e1e1eb..db415cce 100755
--- a/scripts/dbgbmap.py
+++ b/scripts/dbgbmap.py
@@ -4717,18 +4717,19 @@ def main_(ring, disk, mroots=None, *,
             block_cols_ = block_cols
             block_rows_ = mt.ceil(len(bmap) / block_cols)
         else:
+            # prioritize rows at low resolution
+            block_rows_ = min(len(bmap), max(canvas.height, 1)) # was len(bmap)
+            block_cols_ = mt.ceil(len(bmap) / block_rows_)      # was 1
             # divide by 2 until we hit our target ratio, this works
             # well for things that are often powers-of-two
-            block_cols_ = 1
-            block_rows_ = len(bmap)
             while (abs(((canvas.width/(block_cols_*2))
                             / max(canvas.height/mt.ceil(block_rows_/2), 1))
                         - block_ratio)
                     < abs(((canvas.width/block_cols_)
                             / max(canvas.height/block_rows_, 1)))
                         - block_ratio):
-                block_cols_ *= 2
                 block_rows_ = mt.ceil(block_rows_ / 2)
+                block_cols_ *= 2
 
         block_width_ = canvas.width / block_cols_
         block_height_ = canvas.height / block_rows_
diff --git a/scripts/dbgbmapd3.py b/scripts/dbgbmapd3.py
index f3e4e06d..54e2bcd3 100755
--- a/scripts/dbgbmapd3.py
+++ b/scripts/dbgbmapd3.py
@@ -4440,18 +4440,19 @@ def main(disk, output, mroots=None, *,
         block_cols_ = block_cols
         block_rows_ = mt.ceil(len(bmap) / block_cols)
     else:
+        # prioritize rows at low resolution
+        block_rows_ = min(len(bmap), max(height__, 1)) # was len(bmap)
+        block_cols_ = mt.ceil(len(bmap) / block_rows_) # was 1
         # divide by 2 until we hit our target ratio, this works
         # well for things that are often powers-of-two
-        block_cols_ = 1
-        block_rows_ = len(bmap)
         while (abs(((width__/(block_cols_*2))
                         / max(height__/mt.ceil(block_rows_/2), 1))
                     - block_ratio)
                 < abs(((width__/block_cols_)
                         / max(height__/block_rows_, 1)))
                     - block_ratio):
-            block_cols_ *= 2
             block_rows_ = mt.ceil(block_rows_ / 2)
+            block_cols_ *= 2
 
     block_width_ = width__ / block_cols_
     block_height_ = height__ / block_rows_