diff --git a/Misaki.HighPerformance.Jobs/JobScheduler.cs b/Misaki.HighPerformance.Jobs/JobScheduler.cs
index e9691e1..0520cf7 100644
--- a/Misaki.HighPerformance.Jobs/JobScheduler.cs
+++ b/Misaki.HighPerformance.Jobs/JobScheduler.cs
@@ -532,7 +532,7 @@ public sealed unsafe partial class JobScheduler : IJobScheduler, IDisposable
             return JobHandle.Invalid;
         }
 
-        Unsafe.Copy(pJobData, in job);
+        *(T*)pJobData = job;
 
         var jobInfo = new JobInfo
         {
@@ -569,10 +569,7 @@ public sealed unsafe partial class JobScheduler : IJobScheduler, IDisposable
             return JobHandle.Invalid;
         }
 
-        fixed (T* pJob = &job)
-        {
-            NativeMemory.Copy(pJobData, pJob, (nuint)sizeof(T));
-        }
+        *(T*)pJobData = job;
 
         var optimalBatchSize = Math.Max(1, batchSize);
         var totalBatches = (totalIteration + optimalBatchSize - 1) / optimalBatchSize;
@@ -617,10 +614,7 @@ public sealed unsafe partial class JobScheduler : IJobScheduler, IDisposable
             return JobHandle.Invalid;
         }
 
-        fixed (T* pJob = &job)
-        {
-            NativeMemory.Copy(pJobData, pJob, (nuint)sizeof(T));
-        }
+        *(T*)pJobData = job;
 
         var optimalBatchSize = Math.Max(1, batchSize);
         var totalBatches = (totalIteration + optimalBatchSize - 1) / optimalBatchSize;
diff --git a/Misaki.HighPerformance.Jobs/Misaki.HighPerformance.Jobs.csproj b/Misaki.HighPerformance.Jobs/Misaki.HighPerformance.Jobs.csproj
index 05578a5..3e3e220 100644
--- a/Misaki.HighPerformance.Jobs/Misaki.HighPerformance.Jobs.csproj
+++ b/Misaki.HighPerformance.Jobs/Misaki.HighPerformance.Jobs.csproj
@@ -6,7 +6,7 @@
     <Nullable>enable</Nullable>
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
-    <AssemblyVersion>1.5.6</AssemblyVersion>
+    <AssemblyVersion>1.5.7</AssemblyVersion>
     <Version>$(AssemblyVersion)</Version>
     <Authors>Misaki</Authors>
     <PackageProjectUrl>https://git.personalnas.com/Misaki/Misaki.HighPerformance.git</PackageProjectUrl>
diff --git a/Misaki.HighPerformance.LowLevel/Buffer/AllocationManager.cs b/Misaki.HighPerformance.LowLevel/Buffer/AllocationManager.cs
index f45b3ba..83c2419 100644
--- a/Misaki.HighPerformance.LowLevel/Buffer/AllocationManager.cs
+++ b/Misaki.HighPerformance.LowLevel/Buffer/AllocationManager.cs
@@ -54,6 +54,13 @@ public readonly struct AllocationManagerInitOpts
     {
         get; init;
     }
+
+    public static AllocationManagerInitOpts Default => new AllocationManagerInitOpts
+    {
+        ArenaCapacity = 1024 * 1024 * 1024, // 1 GB
+        StackCapacity = 16 * 1024 * 1024, // 16 MB per thread
+        FreeListConcurrencyLevel = Environment.ProcessorCount
+    };
 }
 
 /// <summary>
diff --git a/Misaki.HighPerformance.Test/UnitTest/Jobs/TestJobSystem.cs b/Misaki.HighPerformance.Test/UnitTest/Jobs/TestJobSystem.cs
index dfe7652..511d7dc 100644
--- a/Misaki.HighPerformance.Test/UnitTest/Jobs/TestJobSystem.cs
+++ b/Misaki.HighPerformance.Test/UnitTest/Jobs/TestJobSystem.cs
@@ -22,6 +22,7 @@ public unsafe class TestJobSystem
     [ClassInitialize]
     public static void Initialize(TestContext testContext)
     {
+        AllocationManager.Initialize(AllocationManagerInitOpts.Default);
         s_jobScheduler = new JobScheduler(3);
     }