diff --git a/src/SharpEmu.ShaderCompiler/Resources/ResourceMaterializationCache.cs b/src/SharpEmu.ShaderCompiler/Resources/ResourceMaterializationCache.cs
index 2555701..85fdec6 100644
--- a/src/SharpEmu.ShaderCompiler/Resources/ResourceMaterializationCache.cs
+++ b/src/SharpEmu.ShaderCompiler/Resources/ResourceMaterializationCache.cs
@@ -828,7 +828,61 @@ public sealed class ResourceMaterializationCache
         var refusals = string.Join(",", RefreshRefusalNames.Select((name, index) => FormattableString.Invariant($"{name}:{Interlocked.Exchange(ref _refreshRefusals[index], 0)}")));
         var total = hits + misses;
         return FormattableString.Invariant(
-            $"[PERF][RESOURCE_CACHE] hits={hits} misses={misses} not_found={notFound} stale={stale} stale_unreadable={staleUnreadable} refreshes={refreshes} refused={refusals} uncacheable={uncacheable} hit_rate={(total == 0 ? 0 : hits * 100.0 / total):F1}% {RawReadPrefetch.TakeReport()}");
+            $"[PERF][RESOURCE_CACHE] hits={hits} misses={misses} not_found={notFound} stale={stale} stale_unreadable={staleUnreadable} refreshes={refreshes} refused={refusals} uncacheable={uncacheable} hit_rate={(total == 0 ? 0 : hits * 100.0 / total):F1}% {RawReadPrefetch.TakeReport()}") +
+            TakeStaleDifferenceReport();
+    }
+
+    private static readonly bool StaleDiffEnabled = Environment.GetEnvironmentVariable("SHARPEMU_PROFILE_PERFORMANCE") == "1";
+    private static readonly System.Collections.Concurrent.ConcurrentDictionary<string, long> _staleDifferences = new(StringComparer.Ordinal);
+
+    private static void NoteStaleDifference(Entry stale, Entry built)
+    {
+        var parts = new SortedSet<string>(StringComparer.Ordinal);
+        if (!stale.Specialization.Equals(built.Specialization))
+            parts.Add("spec");
+        DifferingWords("buf", stale.Snapshot.Buffers, built.Snapshot.Buffers, parts);
+        DifferingWords("img", stale.Snapshot.Images, built.Snapshot.Images, parts);
+        DifferingWords("smp", stale.Snapshot.Samplers, built.Snapshot.Samplers, parts);
+        if (!stale.Snapshot.FlattenedResourceTable.AsSpan().SequenceEqual(built.Snapshot.FlattenedResourceTable))
+            parts.Add("table");
+        if (!stale.Snapshot.DeviceAddressRanges.AsSpan().SequenceEqual(built.Snapshot.DeviceAddressRanges))
+            parts.Add("ranges");
+        if (stale.Bytes.Length != built.Bytes.Length || !stale.RangeAddresses.AsSpan().SequenceEqual(built.RangeAddresses))
+            parts.Add("reads_moved");
+        var signature = parts.Count == 0 ? "none" : string.Join("+", parts);
+        _staleDifferences.AddOrUpdate(signature, 1, static (_, count) => count + 1);
+    }
+
+    private static void DifferingWords(string name, uint[][] left, uint[][] right, SortedSet<string> parts)
+    {
+        if (left.Length != right.Length)
+        {
+            parts.Add($"{name}.count");
+            return;
+        }
+
+        for (var index = 0; index < left.Length; index++)
+        {
+            if (left[index].Length != right[index].Length)
+            {
+                parts.Add($"{name}.length");
+                continue;
+            }
+
+            for (var word = 0; word < left[index].Length; word++)
+                if (left[index][word] != right[index][word])
+                    parts.Add($"{name}.w{word}");
+        }
+    }
+
+    private static string TakeStaleDifferenceReport()
+    {
+        if (_staleDifferences.IsEmpty)
+            return string.Empty;
+        var ranked = _staleDifferences.ToArray().OrderByDescending(pair => pair.Value).Take(10).ToArray();
+        _staleDifferences.Clear();
+        return Environment.NewLine + string.Join(Environment.NewLine,
+            ranked.Select(pair => FormattableString.Invariant($"[PERF][RESOURCE_STALE_DIFF] n={pair.Value} changed={pair.Key}")));
     }
 
     // The first part a cached result differs from a fresh one in, or null when they are the same.
@@ -1007,6 +1061,8 @@ public sealed class ResourceMaterializationCache
             }
 
             var built = recorder.Build(plan, inputs, snapshot, specialization, rebase.MemoryBases);
+            if (StaleDiffEnabled && stale is not null && learning is null)
+                NoteStaleDifference(stale, built);
             if (learning is { } pending)
             {
                 var agrees = Difference(pending.Snapshot, pending.From.Specialization, built.Snapshot, built.Specialization) is null;