diff --git a/PERF.md b/PERF.md
index 8493493..03a5e67 100644
--- a/PERF.md
+++ b/PERF.md
@@ -8,14 +8,14 @@
 | drawLine V | 90 | 1.67x | 1.11x | 115.30x |
 | drawLine diag | 35 | 1.14x | 1.06x | 261.49x |
 | drawRect 100x100 | 75 | 1.57x | 1.04x | 250.77x |
-| drawCircle r=16 | 232 | 1.21x | 0.65x | 71.24x |
-| drawCircle r=80 | 56 | 1.16x | 0.61x | 310.93x |
+| drawCircle r=16 | 232 | 1.21x | **0.65x** | 71.24x |
+| drawCircle r=80 | 56 | 1.16x | **0.61x** | 310.93x |
 | fillRect 16x16 | 450 | 1.24x | 1.04x | 39.38x |
-| fillRect 80x80 | 75 | 0.95x | 1.28x | 206.73x |
-| fillRect 320x200 | 60 | 0.93x | 0.43x | 184.62x |
-| fillCircle r=40 | 38 | 0.97x | 1.39x | 347.24x |
+| fillRect 80x80 | 75 | **0.95x** | 1.28x | 206.73x |
+| fillRect 320x200 | 60 | **0.93x** | **0.43x** | 184.62x |
+| fillCircle r=40 | 38 | **0.97x** | 1.39x | 347.24x |
 | samplePixel | 1916 | 3.48x | 1.92x | 18.04x |
-| tileFill | 1252 | 1.73x | 0.93x | 10.44x |
+| tileFill | 1252 | 1.73x | **0.93x** | 10.44x |
 | tileCopy | 997 | 1.80x | 1.02x | 16.96x |
 | tileCopyMasked | 498 | 1.76x | 1.08x | 28.55x |
 | tilePaste | 1106 | 1.94x | 1.09x | 13.53x |
diff --git a/tools/uber-perf-table b/tools/uber-perf-table
index ad6d41f..2492e5d 100755
--- a/tools/uber-perf-table
+++ b/tools/uber-perf-table
@@ -60,7 +60,12 @@ def format_ratio(port_ops, ref_ops):
     if port_ops is None or ref_ops is None or ref_ops == 0:
         return "-"
     ratio = port_ops / ref_ops
-    return f"{ratio:.2f}x"
+    cell = f"{ratio:.2f}x"
+    # Bold sub-parity ratios. DESIGN.md treats the reference port as
+    # the perf floor; ratios below 1.00 are the cells worth attention.
+    if ratio < 1.0:
+        cell = f"**{cell}**"
+    return cell
 
 
 def render_table(port_data, ops_in_order, ref_key):