diff --git a/PerfectNumbers.Core/PerfectNumberConstants.cs b/PerfectNumbers.Core/PerfectNumberConstants.cs
index 98dd3ee..7947dff 100644
--- a/PerfectNumbers.Core/PerfectNumberConstants.cs
+++ b/PerfectNumbers.Core/PerfectNumberConstants.cs
@@ -12,8 +12,8 @@ public static class PerfectNumberConstants
     public static readonly uint PrimesLimit = 1_000_000; //(ulong)Array.MaxLength;// 1_000_000;
     public const int MaxOddPowersCount = 128;
 	public const int PooledArrayThreshold = 64;
-	public static readonly int RollingAccelerators = 298; //SharedGpuContext.Device.MaxNumThreadsPerGroup;
-	public const int ThreadsByAccelerator = 1;
+	public static readonly int RollingAccelerators = 100; //SharedGpuContext.Device.MaxNumThreadsPerGroup;
+	public const int ThreadsByAccelerator = 4096;
     // TODO: Load these limits from the benchmark-driven configuration so CPU and GPU scans stay aligned with the optimal
     // divisor-cycle datasets we generate offline.
     // TODO: Promote these magic numbers into a runtime profile derived from EvenPerfectBitScanner.Benchmarks so we can retune
diff --git a/PerfectNumbers.Core/PrimeOrderCalculator.Cpu.cs b/PerfectNumbers.Core/PrimeOrderCalculator.Cpu.cs
index 7d4da13..679d933 100644
--- a/PerfectNumbers.Core/PrimeOrderCalculator.Cpu.cs
+++ b/PerfectNumbers.Core/PrimeOrderCalculator.Cpu.cs
@@ -1177,7 +1177,7 @@ internal static partial class PrimeOrderCalculator
 					// bool isPrime = HeuristicCombinedPrimeTester.IsPrimeGpu(gpu, composite);
 					bool runOnGpu = RunOnGpu();
 
-					bool isPrime = runOnGpu ? PrimeTester.IsPrime(composite) : HeuristicCombinedPrimeTester.IsPrimeGpu(gpu, composite);
+					bool isPrime = !runOnGpu ? PrimeTester.IsPrime(composite) : HeuristicCombinedPrimeTester.IsPrimeGpu(gpu, composite);
 					// bool isPrime = PrimeTester.IsPrime(composite);
 					// bool isPrime = Open.Numeric.Primes.Prime.Numbers.IsPrime(composite);
 
@@ -1375,6 +1375,7 @@ internal static partial class PrimeOrderCalculator
 
 	private static bool RunOnGpu()
 	{
+		return true;
 		const int GpuFrequency = 1024 - 1;
 
 		int cpuCount = Atomic.Add(target: ref _cpuCount, 1);