diff --git a/src/Benchmarks/Middleware/MiddlewareHelpers.cs b/src/Benchmarks/Middleware/MiddlewareHelpers.cs
index 4aff93401..d1a31c291 100644
--- a/src/Benchmarks/Middleware/MiddlewareHelpers.cs
+++ b/src/Benchmarks/Middleware/MiddlewareHelpers.cs
@@ -1,7 +1,10 @@
 ﻿// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
+using System.Buffers;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Globalization;
 using System.Text;
 using System.Text.Encodings.Web;
@@ -30,27 +33,92 @@ public static int GetMultipleQueriesQueryCount(HttpContext httpContext)
                     : 1;
         }
 
-        public static Task RenderFortunesHtml(IEnumerable<Fortune> model, HttpContext httpContext, HtmlEncoder htmlEncoder)
+        public static async Task RenderFortunesHtml(IEnumerable<Fortune> model, HttpContext httpContext, HtmlEncoder htmlEncoder)
         {
             httpContext.Response.StatusCode = StatusCodes.Status200OK;
             httpContext.Response.ContentType = "text/html; charset=UTF-8";
 
-            var sb = StringBuilderCache.Acquire();
-            sb.Append("<!DOCTYPE html><html><head><title>Fortunes</title></head><body><table><tr><th>id</th><th>message</th></tr>");
+            await httpContext.Response.StartAsync();
+
+            var writer = new BufferWriter<byte>(httpContext.Response.BodyWriter);
+
+            writer.Write("<!DOCTYPE html><html><head><title>Fortunes</title></head><body><table><tr><th>id</th><th>message</th></tr>"u8);
+
             foreach (var item in model)
             {
-                sb.Append("<tr><td>");
-                sb.Append(item.Id.ToString(CultureInfo.InvariantCulture));
-                sb.Append("</td><td>");
-                sb.Append(htmlEncoder.Encode(item.Message));
-                sb.Append("</td></tr>");
+                writer.Write("<tr><td>"u8);
+
+                const int maxFormatInt32Length = 10;
+                var span = writer.GetSpan(maxFormatInt32Length);
+                var res = item.Id.TryFormat(span, out var written, provider: CultureInfo.InvariantCulture);
+                Debug.Assert(res);
+                writer.Advance(written);
+
+                writer.Write("</td><td>"u8);
+                EncodeToPipe(writer, htmlEncoder, item.Message);
+                writer.Write("</td></tr>"u8);
+            }
+
+            writer.Write("</table></body></html>"u8);
+
+            writer.Commit();
+
+            await httpContext.Response.BodyWriter.FlushAsync();
+
+            static void EncodeToPipe(BufferWriter<byte> writer, HtmlEncoder htmlEncoder, string item)
+            {
+                Span<char> buffer = stackalloc char[256];
+                int remaining = item.Length;
+                do
+                {
+                    htmlEncoder.Encode(item.AsSpan()[..remaining], buffer, out var consumed, out var written, isFinalBlock: true);
+                    remaining -= consumed;
+                    Encoding.UTF8.GetBytes(buffer.Slice(0, written), writer);
+                } while (remaining != 0);
+            }
+        }
+    }
+
+    internal class BufferWriter<T> : IBufferWriter<T>
+    {
+        private readonly IBufferWriter<T> _inner;
+        private Memory<T> _memory;
+        private int _buffered;
+
+        public BufferWriter(IBufferWriter<T> writer)
+        {
+            _inner = writer;
+        }
+
+        public void Advance(int count)
+        {
+            _memory = _memory.Slice(count);
+            _buffered += count;
+        }
+
+        public void Commit()
+        {
+            if (_buffered != 0)
+            {
+                _inner.Advance(_buffered);
+                _buffered = 0;
+                _memory = default;
+            }
+        }
+
+        public Memory<T> GetMemory(int sizeHint = 0)
+        {
+            if (_memory.Length == 0 || _memory.Length < sizeHint)
+            {
+                Commit();
+                _memory = _inner.GetMemory(sizeHint);
             }
+            return _memory;
+        }
 
-            sb.Append("</table></body></html>");
-            var response = StringBuilderCache.GetStringAndRelease(sb);
-            // fortunes includes multibyte characters so response.Length is incorrect
-            httpContext.Response.ContentLength = Encoding.UTF8.GetByteCount(response);
-            return httpContext.Response.WriteAsync(response);
+        public Span<T> GetSpan(int sizeHint = 0)
+        {
+            return GetMemory(sizeHint).Span;
         }
     }
 }

id	message
"); - sb.Append(item.Id.ToString(CultureInfo.InvariantCulture)); - sb.Append("	"); - sb.Append(htmlEncoder.Encode(item.Message)); - sb.Append("
"u8); + + const int maxFormatInt32Length = 10; + var span = writer.GetSpan(maxFormatInt32Length); + var res = item.Id.TryFormat(span, out var written, provider: CultureInfo.InvariantCulture); + Debug.Assert(res); + writer.Advance(written); + + writer.Write("	"u8); + EncodeToPipe(writer, htmlEncoder, item.Message); + writer.Write("