Additional checks will be skipped in bydivisor mode to speed up calculations. Console output extended.

EvenPerfectBitScanner/Program.cs

@@ -1440,7 +1440,7 @@ internal static class Program
 		}
 
 		// Fast residue-based composite check for p using small primes
-		if (!_useDivisor && IsCompositeByResidues(p))
+		if (!_useDivisor && !_useByDivisorMode && IsCompositeByResidues(p))
 		{
 			searchedMersenne = false;
 			detailedCheck = false;
@@ -1450,6 +1450,8 @@ internal static class Program
 
 		// If primes-device=gpu, route p primality through GPU-assisted sieve (optional MR later)
 		// TODO: Add deterministic Miller–Rabin rounds in GPU path for 64-bit range.
+		if (!_useByDivisorMode)
+		{
 			bool isPrimeP = GpuContextPool.ForceCpu
 					? PrimeTesters.Value!.IsPrime(p, CancellationToken.None)
 					: PrimeTesters.Value!.IsPrimeGpu(p, CancellationToken.None);
@@ -1458,6 +1460,7 @@ internal static class Program
 				_lastCompositeP = true;
 				return false;
 			}
+		}
 
 		searchedMersenne = true;
 		if (_useByDivisorMode)

PerfectNumbers.Core/Gpu/MersenneNumberDivisorByDivisorGpuTester.cs

@@ -274,12 +274,19 @@ public sealed class MersenneNumberDivisorByDivisorGpuTester
 			}
 
 			int offset = 0;
+			int consoleStatus = 0;
 			while (offset < primes.Length)
 			{
 				int batchSize = Math.Min(_owner._gpuBatchSize, primes.Length - offset);
 				Span<ulong> primeSpan = _primesHost.AsSpan(0, batchSize);
 				primes.Slice(offset, batchSize).CopyTo(primeSpan);
 
+				if (++consoleStatus == PerfectNumberConstants.ConsoleInterval)
+				{
+					Console.WriteLine($"...processed by-divisor candidate = {primes[0]}");
+					consoleStatus = 0;
+				}
+
 				var primesView = _primesBuffer.View.SubView(0, batchSize);
 				var hitsView = _hitsBuffer.View.SubView(0, batchSize);