diff --git a/PerfectNumbers.Core/Gpu/GpuKernelLease.cs b/PerfectNumbers.Core/Gpu/GpuKernelLease.cs
index 4d4f6ee..914f026 100644
--- a/PerfectNumbers.Core/Gpu/GpuKernelLease.cs
+++ b/PerfectNumbers.Core/Gpu/GpuKernelLease.cs
@@ -6,7 +6,7 @@ using static PerfectNumbers.Core.Gpu.GpuContextPool;
 
 namespace PerfectNumbers.Core.Gpu;
 
-public sealed class GpuKernelLease : IDisposable
+public sealed class GpuKernelLease
 {
     private static readonly ConcurrentQueue<GpuKernelLease> Pool = new();
 
@@ -702,8 +702,7 @@ public sealed class GpuKernelLease : IDisposable
 
     public void Dispose()
     {
-        Dispose(disposing: true);
-        System.GC.SuppressFinalize(this);
+        Dispose(disposing: false);
     }
 
     public readonly struct ExecutionScope
@@ -715,7 +714,7 @@ public sealed class GpuKernelLease : IDisposable
             _lock = sync;
             if (_lock is not null)
             {
-                // Monitor.Enter(_lock);
+                Monitor.Enter(_lock);
             }
         }
 
@@ -723,7 +722,7 @@ public sealed class GpuKernelLease : IDisposable
         {
             if (_lock is not null)
             {
-                // Monitor.Exit(_lock);
+                Monitor.Exit(_lock);
             }
         }
     }
diff --git a/PerfectNumbers.Core/PrimeOrderCalculator.Cpu.cs b/PerfectNumbers.Core/PrimeOrderCalculator.Cpu.cs
index ec06822..b120919 100644
--- a/PerfectNumbers.Core/PrimeOrderCalculator.Cpu.cs
+++ b/PerfectNumbers.Core/PrimeOrderCalculator.Cpu.cs
@@ -82,10 +82,6 @@ internal static partial class PrimeOrderCalculator
 		for (int i = 0; i < length; i++)
 		{
 			ulong factor = factorSpan[i].Value;
-			if (factor == 0UL)
-			{
-				continue;
-			}
 			ulong reduced = phi / factor;
 			if (Pow2EqualsOneCpu(reduced, prime, divisorData))
 			{
@@ -643,16 +639,16 @@ internal static partial class PrimeOrderCalculator
 	private static bool Pow2EqualsOneCpu(ulong exponent, ulong prime, in MontgomeryDivisorData divisorData)
 	{
 		// if (IsGpuPow2Allowed)
-		// {
+		{
 			ulong remainder = exponent.Pow2MontgomeryModWindowedGpu(divisorData, false);
 			// GpuPow2ModStatus status = PrimeOrderGpuHeuristics.TryPow2Mod(exponent, prime, out ulong remainder, divisorData);
 			// if (status == GpuPow2ModStatus.Success)
 			// {
 				return remainder == 1UL;
 			// }
-		// }
+		}
 
-		// return exponent.Pow2MontgomeryModWindowedCpu(divisorData, keepMontgomery: false) == 1UL;
+		return exponent.Pow2MontgomeryModWindowedCpu(divisorData, keepMontgomery: false) == 1UL;
 	}
 
 	// [ThreadStatic]
@@ -748,21 +744,21 @@ internal static partial class PrimeOrderCalculator
 			// int dictionaryCount = counts.Count;
 			// if (dictionaryCount <= FactorSlotCount)
 			// {
-				int copyIndex = 0;
-				foreach (KeyValuePair<ulong, int> entry in counts)
-				{
-					primeSlots[copyIndex] = entry.Key;
-					exponentSlots[copyIndex] = entry.Value;
-					copyIndex++;
-				}
+				// int copyIndex = 0;
+				// foreach (KeyValuePair<ulong, int> entry in counts)
+				// {
+				// 	primeSlots[copyIndex] = entry.Key;
+				// 	exponentSlots[copyIndex] = entry.Value;
+				// 	copyIndex++;
+				// }
 
-				factorCount = copyIndex;
-				ThreadStaticPools.ReturnUlongIntDictionary(counts);
-				counts = null;
+				// factorCount = copyIndex;
+				// ThreadStaticPools.ReturnUlongIntDictionary(counts);
+				// counts = null;
 			// }
 			// else
 			// {
-				// useDictionary = true;
+				useDictionary = true;
 				// factorCount = dictionaryCount;
 			// }
 		}