diff --git a/com.unity.render-pipelines.core/Runtime/Debugging/DebugFrameTiming.cs b/com.unity.render-pipelines.core/Runtime/Debugging/DebugFrameTiming.cs
index 65023880049..3a4903ba38d 100644
--- a/com.unity.render-pipelines.core/Runtime/Debugging/DebugFrameTiming.cs
+++ b/com.unity.render-pipelines.core/Runtime/Debugging/DebugFrameTiming.cs
@@ -1,10 +1,10 @@
+//#define RTPROFILER_DEBUG
+
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using UnityEngine;
 
-//#define RTPROFILER_DEBUG
-
 namespace UnityEngine.Rendering
 {
     public class DebugFrameTiming
@@ -13,8 +13,8 @@ public class DebugFrameTiming
         const string k_MsFormatString = "{0:F2}ms";
         const float k_RefreshRate = 1f / 5f;
 
-        internal FrameTimeSampleHistory m_FrameHistory = new();
-        internal BottleneckHistory m_BottleneckHistory = new();
+        internal FrameTimeSampleHistory m_FrameHistory;
+        internal BottleneckHistory m_BottleneckHistory;
 
         /// <summary>
         /// Size of the Bottleneck History Window in number of samples.
@@ -29,6 +29,12 @@ public class DebugFrameTiming
         FrameTiming[] m_Timing = new FrameTiming[1];
         FrameTimeSample m_Sample = new FrameTimeSample();
 
+        public DebugFrameTiming()
+        {
+            m_FrameHistory = new FrameTimeSampleHistory(sampleHistorySize);
+            m_BottleneckHistory = new BottleneckHistory(bottleneckHistorySize);
+        }
+
         /// <summary>
         /// Update timing data from profiling counters.
         /// </summary>
@@ -158,16 +164,16 @@ public void RegisterDebugUI(List<DebugUI.Widget> list)
                     new DebugUI.IntField
                     {
                         displayName = "Frame Time Sample History Size",
-                        getter = () => SampleHistorySize,
-                        setter = (value) => { SampleHistorySize = value; },
+                        getter = () => sampleHistorySize,
+                        setter = (value) => { sampleHistorySize = value; },
                         min = () => 1,
                         max = () => 100
                     },
                     new DebugUI.IntField
                     {
                         displayName = "Bottleneck History Size",
-                        getter = () => BottleneckHistorySize,
-                        setter = (value) => { BottleneckHistorySize = value; },
+                        getter = () => bottleneckHistorySize,
+                        setter = (value) => { bottleneckHistorySize = value; },
                         min = () => 1,
                         max = () => 100
                     },
diff --git a/com.unity.render-pipelines.core/Runtime/Debugging/FrameTiming/FrameTimeBottleneck.cs b/com.unity.render-pipelines.core/Runtime/Debugging/FrameTiming/FrameTimeBottleneck.cs
index 9a1bf32251c..b8b817823d9 100644
--- a/com.unity.render-pipelines.core/Runtime/Debugging/FrameTiming/FrameTimeBottleneck.cs
+++ b/com.unity.render-pipelines.core/Runtime/Debugging/FrameTiming/FrameTimeBottleneck.cs
@@ -33,14 +33,23 @@ internal struct BottleneckHistogram
     /// </summary>
     internal class BottleneckHistory
     {
+        public BottleneckHistory(int initialCapacity)
+        {
+            m_Bottlenecks.Capacity = initialCapacity;
+        }
+
         List<PerformanceBottleneck> m_Bottlenecks = new();
 
         internal BottleneckHistogram Histogram;
 
         internal void DiscardOldSamples(int historySize)
         {
+            Debug.Assert(historySize > 0, "Invalid sampleHistorySize");
+
             while (m_Bottlenecks.Count >= historySize)
                 m_Bottlenecks.RemoveAt(0);
+
+            m_Bottlenecks.Capacity = historySize;
         }
 
         internal void AddBottleneckFromAveragedSample(FrameTimeSample frameHistorySampleAverage)
diff --git a/com.unity.render-pipelines.core/Runtime/Debugging/FrameTiming/FrameTimeSample.cs b/com.unity.render-pipelines.core/Runtime/Debugging/FrameTiming/FrameTimeSample.cs
index ac4f04177d3..3870d757afe 100644
--- a/com.unity.render-pipelines.core/Runtime/Debugging/FrameTiming/FrameTimeSample.cs
+++ b/com.unity.render-pipelines.core/Runtime/Debugging/FrameTiming/FrameTimeSample.cs
@@ -31,6 +31,11 @@ internal FrameTimeSample(float initValue)
     /// </summary>
     class FrameTimeSampleHistory
     {
+        public FrameTimeSampleHistory(int initialCapacity)
+        {
+            m_Samples.Capacity = initialCapacity;
+        }
+
         List<FrameTimeSample> m_Samples = new();
 
         internal FrameTimeSample SampleAverage;
@@ -112,8 +117,12 @@ void ForEachSampleMember(ref FrameTimeSample aggregate, FrameTimeSample sample,
 
         internal void DiscardOldSamples(int sampleHistorySize)
         {
+            Debug.Assert(sampleHistorySize > 0, "Invalid sampleHistorySize");
+
             while (m_Samples.Count >= sampleHistorySize)
                 m_Samples.RemoveAt(0);
+
+            m_Samples.Capacity = sampleHistorySize;
         }
 
         internal void Clear()