diff --git a/src/Numerics/LinearAlgebra/Complex/DenseMatrix.cs b/src/Numerics/LinearAlgebra/Complex/DenseMatrix.cs
index 8b001712..93dfcb87 100644
--- a/src/Numerics/LinearAlgebra/Complex/DenseMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex/DenseMatrix.cs
@@ -150,7 +150,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
         public DenseMatrix(Matrix<Complex> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Complex/DiagonalMatrix.cs b/src/Numerics/LinearAlgebra/Complex/DiagonalMatrix.cs
index ffb81b0e..46f9c0ce 100644
--- a/src/Numerics/LinearAlgebra/Complex/DiagonalMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex/DiagonalMatrix.cs
@@ -151,7 +151,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
         public DiagonalMatrix(Matrix<Complex> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Complex/SparseMatrix.cs b/src/Numerics/LinearAlgebra/Complex/SparseMatrix.cs
index c5764779..63c5e87f 100644
--- a/src/Numerics/LinearAlgebra/Complex/SparseMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex/SparseMatrix.cs
@@ -180,7 +180,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex
         public SparseMatrix(Matrix<Complex> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Complex32/DenseMatrix.cs b/src/Numerics/LinearAlgebra/Complex32/DenseMatrix.cs
index b5cf03fe..e95c21f2 100644
--- a/src/Numerics/LinearAlgebra/Complex32/DenseMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex32/DenseMatrix.cs
@@ -150,7 +150,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex32
         public DenseMatrix(Matrix<Complex32> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Complex32/DiagonalMatrix.cs b/src/Numerics/LinearAlgebra/Complex32/DiagonalMatrix.cs
index 28eb1a36..f95ceda3 100644
--- a/src/Numerics/LinearAlgebra/Complex32/DiagonalMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex32/DiagonalMatrix.cs
@@ -151,7 +151,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex32
         public DiagonalMatrix(Matrix<Complex32> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Complex32/SparseMatrix.cs b/src/Numerics/LinearAlgebra/Complex32/SparseMatrix.cs
index 5ec92abe..2e672c06 100644
--- a/src/Numerics/LinearAlgebra/Complex32/SparseMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Complex32/SparseMatrix.cs
@@ -180,7 +180,7 @@ namespace MathNet.Numerics.LinearAlgebra.Complex32
         public SparseMatrix(Matrix<Complex32> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Double/DenseMatrix.cs b/src/Numerics/LinearAlgebra/Double/DenseMatrix.cs
index e8126208..46176dc2 100644
--- a/src/Numerics/LinearAlgebra/Double/DenseMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Double/DenseMatrix.cs
@@ -150,7 +150,7 @@ namespace MathNet.Numerics.LinearAlgebra.Double
         public DenseMatrix(Matrix<double> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Double/DiagonalMatrix.cs b/src/Numerics/LinearAlgebra/Double/DiagonalMatrix.cs
index 32737edb..6b916612 100644
--- a/src/Numerics/LinearAlgebra/Double/DiagonalMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Double/DiagonalMatrix.cs
@@ -150,7 +150,7 @@ namespace MathNet.Numerics.LinearAlgebra.Double
         public DiagonalMatrix(Matrix<double> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Double/SparseMatrix.cs b/src/Numerics/LinearAlgebra/Double/SparseMatrix.cs
index 335847ec..42eca740 100644
--- a/src/Numerics/LinearAlgebra/Double/SparseMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Double/SparseMatrix.cs
@@ -179,7 +179,7 @@ namespace MathNet.Numerics.LinearAlgebra.Double
         public SparseMatrix(Matrix<double> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Generic/Matrix.cs b/src/Numerics/LinearAlgebra/Generic/Matrix.cs
index c152d219..4305f742 100644
--- a/src/Numerics/LinearAlgebra/Generic/Matrix.cs
+++ b/src/Numerics/LinearAlgebra/Generic/Matrix.cs
@@ -286,7 +286,7 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
         public virtual Matrix<T> Clone()
         {
             var result = CreateMatrix(RowCount, ColumnCount);
-            Storage.CopyTo(result.Storage, skipClearing: true);
+            Storage.CopyToUnchecked(result.Storage, skipClearing: true);
             return result;
         }
 
@@ -309,17 +309,6 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
                 throw new ArgumentNullException("target");
             }
 
-            if (ReferenceEquals(this, target) || ReferenceEquals(Storage, target.Storage))
-            {
-                return;
-            }
-
-            if (RowCount != target.RowCount || ColumnCount != target.ColumnCount)
-            {
-                var message = string.Format(Resources.ArgumentMatrixDimensions2, RowCount + "x" + ColumnCount, target.RowCount + "x" + target.ColumnCount);
-                throw new ArgumentException(message, "target");
-            }
-
             Storage.CopyTo(target.Storage);
         }
 
@@ -1485,8 +1474,8 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
             }
 
             var result = CreateMatrix(RowCount, ColumnCount + right.ColumnCount, fullyMutable: true);
-            Storage.CopySubMatrixTo(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount, skipClearing: true);
-            right.Storage.CopySubMatrixTo(result.Storage, 0, 0, right.RowCount, 0, ColumnCount, right.ColumnCount, skipClearing: true);
+            Storage.CopySubMatrixToUnchecked(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount, skipClearing: true);
+            right.Storage.CopySubMatrixToUnchecked(result.Storage, 0, 0, right.RowCount, 0, ColumnCount, right.ColumnCount, skipClearing: true);
             return result;
         }
 
@@ -1517,8 +1506,8 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
                 throw new ArgumentException(Resources.ArgumentMatrixSameColumnDimension);
             }
 
-            Storage.CopySubMatrixTo(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount);
-            right.Storage.CopySubMatrixTo(result.Storage, 0, 0, right.RowCount, 0, ColumnCount, right.ColumnCount);
+            Storage.CopySubMatrixToUnchecked(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount);
+            right.Storage.CopySubMatrixToUnchecked(result.Storage, 0, 0, right.RowCount, 0, ColumnCount, right.ColumnCount);
         }
 
         /// <summary>
@@ -1541,8 +1530,8 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
             }
 
             var result = CreateMatrix(RowCount + lower.RowCount, ColumnCount, fullyMutable: true);
-            Storage.CopySubMatrixTo(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount, skipClearing: true);
-            lower.Storage.CopySubMatrixTo(result.Storage, 0, RowCount, lower.RowCount, 0, 0, lower.ColumnCount, skipClearing: true);
+            Storage.CopySubMatrixToUnchecked(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount, skipClearing: true);
+            lower.Storage.CopySubMatrixToUnchecked(result.Storage, 0, RowCount, lower.RowCount, 0, 0, lower.ColumnCount, skipClearing: true);
             return result;
         }
 
@@ -1575,8 +1564,8 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
                 throw DimensionsDontMatch<ArgumentException>(this, result, "result");
             }
 
-            Storage.CopySubMatrixTo(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount);
-            lower.Storage.CopySubMatrixTo(result.Storage, 0, RowCount, lower.RowCount, 0, 0, lower.ColumnCount);
+            Storage.CopySubMatrixToUnchecked(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount);
+            lower.Storage.CopySubMatrixToUnchecked(result.Storage, 0, RowCount, lower.RowCount, 0, 0, lower.ColumnCount);
         }
 
         /// <summary>
@@ -1595,8 +1584,8 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
             }
 
             var result = CreateMatrix(RowCount + lower.RowCount, ColumnCount + lower.ColumnCount, fullyMutable: true);
-            Storage.CopySubMatrixTo(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount);
-            lower.Storage.CopySubMatrixTo(result.Storage, 0, RowCount, lower.RowCount, 0, ColumnCount, lower.ColumnCount);
+            Storage.CopySubMatrixToUnchecked(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount);
+            lower.Storage.CopySubMatrixToUnchecked(result.Storage, 0, RowCount, lower.RowCount, 0, ColumnCount, lower.ColumnCount);
             return result;
         }
 
@@ -1625,8 +1614,8 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
                 throw DimensionsDontMatch<ArgumentException>(this, result, "result");
             }
 
-            Storage.CopySubMatrixTo(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount);
-            lower.Storage.CopySubMatrixTo(result.Storage, 0, RowCount, lower.RowCount, 0, ColumnCount, lower.ColumnCount);
+            Storage.CopySubMatrixToUnchecked(result.Storage, 0, 0, RowCount, 0, 0, ColumnCount);
+            lower.Storage.CopySubMatrixToUnchecked(result.Storage, 0, RowCount, lower.RowCount, 0, ColumnCount, lower.ColumnCount);
         }
 
         /// <summary>Calculates the L1 norm.</summary>
diff --git a/src/Numerics/LinearAlgebra/Single/DenseMatrix.cs b/src/Numerics/LinearAlgebra/Single/DenseMatrix.cs
index cde0f437..ac2a119a 100644
--- a/src/Numerics/LinearAlgebra/Single/DenseMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Single/DenseMatrix.cs
@@ -150,7 +150,7 @@ namespace MathNet.Numerics.LinearAlgebra.Single
         public DenseMatrix(Matrix<float> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Single/DiagonalMatrix.cs b/src/Numerics/LinearAlgebra/Single/DiagonalMatrix.cs
index 41fdc738..9fb8ca13 100644
--- a/src/Numerics/LinearAlgebra/Single/DiagonalMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Single/DiagonalMatrix.cs
@@ -150,7 +150,7 @@ namespace MathNet.Numerics.LinearAlgebra.Single
         public DiagonalMatrix(Matrix<float> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Single/SparseMatrix.cs b/src/Numerics/LinearAlgebra/Single/SparseMatrix.cs
index 52b3596d..b9039618 100644
--- a/src/Numerics/LinearAlgebra/Single/SparseMatrix.cs
+++ b/src/Numerics/LinearAlgebra/Single/SparseMatrix.cs
@@ -179,7 +179,7 @@ namespace MathNet.Numerics.LinearAlgebra.Single
         public SparseMatrix(Matrix<float> matrix)
             : this(matrix.RowCount, matrix.ColumnCount)
         {
-            matrix.Storage.CopyTo(Storage, skipClearing: true);
+            matrix.Storage.CopyToUnchecked(Storage, skipClearing: true);
         }
 
         /// <summary>
diff --git a/src/Numerics/LinearAlgebra/Storage/DenseColumnMajorMatrixStorage.cs b/src/Numerics/LinearAlgebra/Storage/DenseColumnMajorMatrixStorage.cs
index 1a654550..4bd4f658 100644
--- a/src/Numerics/LinearAlgebra/Storage/DenseColumnMajorMatrixStorage.cs
+++ b/src/Numerics/LinearAlgebra/Storage/DenseColumnMajorMatrixStorage.cs
@@ -68,13 +68,12 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        /// <remarks>Parameters assumed to be validated already.</remarks>
-        public override void CopyTo(MatrixStorage<T> target, bool skipClearing = false)
+        internal override void CopyToUnchecked(MatrixStorage<T> target, bool skipClearing = false)
         {
             var denseTarget = target as DenseColumnMajorMatrixStorage<T>;
             if (denseTarget != null)
             {
-                CopyTo(denseTarget);
+                CopyToUnchecked(denseTarget);
                 return;
             }
 
@@ -89,29 +88,13 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        void CopyTo(DenseColumnMajorMatrixStorage<T> target)
+        void CopyToUnchecked(DenseColumnMajorMatrixStorage<T> target)
         {
-            if (ReferenceEquals(this, target))
-            {
-                return;
-            }
-
-            if (target == null)
-            {
-                throw new ArgumentNullException("target");
-            }
-
-            if (RowCount != target.RowCount || ColumnCount != target.ColumnCount)
-            {
-                var message = string.Format(Resources.ArgumentMatrixDimensions2, RowCount + "x" + ColumnCount, target.RowCount + "x" + target.ColumnCount);
-                throw new ArgumentException(message, "target");
-            }
-
             //Buffer.BlockCopy(Data, 0, target.Data, 0, Data.Length * System.Runtime.InteropServices.Marshal.SizeOf(typeof(T)));
             Array.Copy(Data, 0, target.Data, 0, Data.Length);
         }
 
-        public override void CopySubMatrixTo(MatrixStorage<T> target,
+        internal override void CopySubMatrixToUnchecked(MatrixStorage<T> target,
             int sourceRowIndex, int targetRowIndex, int rowCount,
             int sourceColumnIndex, int targetColumnIndex, int columnCount,
             bool skipClearing = false)
@@ -119,33 +102,19 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             var denseTarget = target as DenseColumnMajorMatrixStorage<T>;
             if (denseTarget != null)
             {
-                CopySubMatrixTo(denseTarget, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount);
+                CopySubMatrixToUnchecked(denseTarget, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount);
                 return;
             }
 
             // FALL BACK
 
-            base.CopySubMatrixTo(target, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount, skipClearing);
+            base.CopySubMatrixToUnchecked(target, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount, skipClearing);
         }
 
-        void CopySubMatrixTo(DenseColumnMajorMatrixStorage<T> target,
+        void CopySubMatrixToUnchecked(DenseColumnMajorMatrixStorage<T> target,
             int sourceRowIndex, int targetRowIndex, int rowCount,
             int sourceColumnIndex, int targetColumnIndex, int columnCount)
         {
-            if (target == null)
-            {
-                throw new ArgumentNullException("target");
-            }
-
-            if (ReferenceEquals(this, target))
-            {
-                throw new NotSupportedException();
-            }
-
-            ValidateSubMatrixRange(target,
-                sourceRowIndex, targetRowIndex, rowCount,
-                sourceColumnIndex, targetColumnIndex, columnCount);
-
             for (int j = sourceColumnIndex, jj = targetColumnIndex; j < sourceColumnIndex + columnCount; j++, jj++)
             {
                 //Buffer.BlockCopy(Data, j*RowCount + sourceRowIndex, target.Data, jj*target.RowCount + targetRowIndex, rowCount * System.Runtime.InteropServices.Marshal.SizeOf(typeof(T)));
diff --git a/src/Numerics/LinearAlgebra/Storage/DiagonalMatrixStorage.cs b/src/Numerics/LinearAlgebra/Storage/DiagonalMatrixStorage.cs
index ab01ad4a..78a19d23 100644
--- a/src/Numerics/LinearAlgebra/Storage/DiagonalMatrixStorage.cs
+++ b/src/Numerics/LinearAlgebra/Storage/DiagonalMatrixStorage.cs
@@ -143,27 +143,26 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             return hash;
         }
 
-        /// <remarks>Parameters assumed to be validated already.</remarks>
-        public override void CopyTo(MatrixStorage<T> target, bool skipClearing = false)
+        internal override void CopyToUnchecked(MatrixStorage<T> target, bool skipClearing = false)
         {
             var diagonalTarget = target as DiagonalMatrixStorage<T>;
             if (diagonalTarget != null)
             {
-                CopyTo(diagonalTarget);
+                CopyToUnchecked(diagonalTarget);
                 return;
             }
 
             var denseTarget = target as DenseColumnMajorMatrixStorage<T>;
             if (denseTarget != null)
             {
-                CopyTo(denseTarget, skipClearing);
+                CopyToUnchecked(denseTarget, skipClearing);
                 return;
             }
 
             var sparseTarget = target as SparseCompressedRowMatrixStorage<T>;
             if (sparseTarget != null)
             {
-                CopyTo(sparseTarget, skipClearing);
+                CopyToUnchecked(sparseTarget, skipClearing);
                 return;
             }
 
@@ -180,41 +179,14 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        void CopyTo(DiagonalMatrixStorage<T> target)
+        void CopyToUnchecked(DiagonalMatrixStorage<T> target)
         {
-            if (ReferenceEquals(this, target))
-            {
-                return;
-            }
-
-            if (target == null)
-            {
-                throw new ArgumentNullException("target");
-            }
-
-            if (RowCount != target.RowCount || ColumnCount != target.ColumnCount)
-            {
-                var message = string.Format(Resources.ArgumentMatrixDimensions2, RowCount + "x" + ColumnCount, target.RowCount + "x" + target.ColumnCount);
-                throw new ArgumentException(message, "target");
-            }
-
             //Buffer.BlockCopy(Data, 0, target.Data, 0, Data.Length * System.Runtime.InteropServices.Marshal.SizeOf(typeof(T)));
             Array.Copy(Data, 0, target.Data, 0, Data.Length);
         }
 
-        void CopyTo(SparseCompressedRowMatrixStorage<T> target, bool skipClearing)
+        void CopyToUnchecked(SparseCompressedRowMatrixStorage<T> target, bool skipClearing)
         {
-            if (target == null)
-            {
-                throw new ArgumentNullException("target");
-            }
-
-            if (RowCount != target.RowCount || ColumnCount != target.ColumnCount)
-            {
-                var message = string.Format(Resources.ArgumentMatrixDimensions2, RowCount + "x" + ColumnCount, target.RowCount + "x" + target.ColumnCount);
-                throw new ArgumentException(message, "target");
-            }
-
             if (!skipClearing)
             {
                 target.Clear();
@@ -226,19 +198,8 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        void CopyTo(DenseColumnMajorMatrixStorage<T> target, bool skipClearing)
+        void CopyToUnchecked(DenseColumnMajorMatrixStorage<T> target, bool skipClearing)
         {
-            if (target == null)
-            {
-                throw new ArgumentNullException("target");
-            }
-
-            if (RowCount != target.RowCount || ColumnCount != target.ColumnCount)
-            {
-                var message = string.Format(Resources.ArgumentMatrixDimensions2, RowCount + "x" + ColumnCount, target.RowCount + "x" + target.ColumnCount);
-                throw new ArgumentException(message, "target");
-            }
-
             if (!skipClearing)
             {
                 target.Clear();
@@ -250,7 +211,7 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        public override void CopySubMatrixTo(MatrixStorage<T> target,
+        internal override void CopySubMatrixToUnchecked(MatrixStorage<T> target,
             int sourceRowIndex, int targetRowIndex, int rowCount,
             int sourceColumnIndex, int targetColumnIndex, int columnCount,
             bool skipClearing = false)
@@ -258,43 +219,33 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             var denseTarget = target as DenseColumnMajorMatrixStorage<T>;
             if (denseTarget != null)
             {
-                CopySubMatrixTo(denseTarget, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount, skipClearing);
+                CopySubMatrixToUnchecked(denseTarget, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount, skipClearing);
                 return;
             }
 
             var diagonalTarget = target as DiagonalMatrixStorage<T>;
             if (diagonalTarget != null)
             {
-                CopySubMatrixTo(diagonalTarget, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount);
+                CopySubMatrixToUnchecked(diagonalTarget, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount);
                 return;
             }
 
             var sparseTarget = target as SparseCompressedRowMatrixStorage<T>;
             if (sparseTarget != null)
             {
-                CopySubMatrixTo(sparseTarget, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount, skipClearing);
+                CopySubMatrixToUnchecked(sparseTarget, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount, skipClearing);
                 return;
             }
 
             // FALL BACK
 
-            base.CopySubMatrixTo(target, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount, skipClearing);
+            base.CopySubMatrixToUnchecked(target, sourceRowIndex, targetRowIndex, rowCount, sourceColumnIndex, targetColumnIndex, columnCount, skipClearing);
         }
 
-        void CopySubMatrixTo(DiagonalMatrixStorage<T> target,
+        void CopySubMatrixToUnchecked(DiagonalMatrixStorage<T> target,
             int sourceRowIndex, int targetRowIndex, int rowCount,
             int sourceColumnIndex, int targetColumnIndex, int columnCount)
         {
-            if (target == null)
-            {
-                throw new ArgumentNullException("target");
-            }
-
-            if (ReferenceEquals(this, target))
-            {
-                throw new NotSupportedException();
-            }
-
             if (sourceRowIndex - sourceColumnIndex != targetRowIndex - targetColumnIndex)
             {
                 if (Data.Any(x => !_zero.Equals(x)))
@@ -306,10 +257,6 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
                 return;
             }
 
-            ValidateSubMatrixRange(target,
-                sourceRowIndex, targetRowIndex, rowCount,
-                sourceColumnIndex, targetColumnIndex, columnCount);
-
             var beginInclusive = Math.Max(sourceRowIndex, sourceColumnIndex);
             var endExclusive = Math.Min(sourceRowIndex + rowCount, sourceColumnIndex + columnCount);
             if (endExclusive > beginInclusive)
@@ -319,20 +266,11 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        void CopySubMatrixTo(DenseColumnMajorMatrixStorage<T> target,
+        void CopySubMatrixToUnchecked(DenseColumnMajorMatrixStorage<T> target,
             int sourceRowIndex, int targetRowIndex, int rowCount,
             int sourceColumnIndex, int targetColumnIndex, int columnCount,
             bool skipClearing)
         {
-            if (target == null)
-            {
-                throw new ArgumentNullException("target");
-            }
-
-            ValidateSubMatrixRange(target,
-                sourceRowIndex, targetRowIndex, rowCount,
-                sourceColumnIndex, targetColumnIndex, columnCount);
-
             if (!skipClearing)
             {
                 target.Clear(targetRowIndex, rowCount, targetColumnIndex, columnCount);
@@ -379,20 +317,11 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        void CopySubMatrixTo(SparseCompressedRowMatrixStorage<T> target,
+        void CopySubMatrixToUnchecked(SparseCompressedRowMatrixStorage<T> target,
             int sourceRowIndex, int targetRowIndex, int rowCount,
             int sourceColumnIndex, int targetColumnIndex, int columnCount,
             bool skipClearing)
         {
-            if (target == null)
-            {
-                throw new ArgumentNullException("target");
-            }
-
-            ValidateSubMatrixRange(target,
-                sourceRowIndex, targetRowIndex, rowCount,
-                sourceColumnIndex, targetColumnIndex, columnCount);
-
             if (!skipClearing)
             {
                 target.Clear(targetRowIndex, rowCount, targetColumnIndex, columnCount);
diff --git a/src/Numerics/LinearAlgebra/Storage/MatrixStorage.cs b/src/Numerics/LinearAlgebra/Storage/MatrixStorage.cs
index f9f40e93..b5ce7f2d 100644
--- a/src/Numerics/LinearAlgebra/Storage/MatrixStorage.cs
+++ b/src/Numerics/LinearAlgebra/Storage/MatrixStorage.cs
@@ -195,8 +195,28 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             return hash;
         }
 
-        /// <remarks>Parameters assumed to be validated already.</remarks>
-        public virtual void CopyTo(MatrixStorage<T> target, bool skipClearing = false)
+        public void CopyTo(MatrixStorage<T> target, bool skipClearing = false)
+        {
+            if (target == null)
+            {
+                throw new ArgumentNullException("target");
+            }
+
+            if (ReferenceEquals(this, target))
+            {
+                return;
+            }
+
+            if (RowCount != target.RowCount || ColumnCount != target.ColumnCount)
+            {
+                var message = string.Format(Resources.ArgumentMatrixDimensions2, RowCount + "x" + ColumnCount, target.RowCount + "x" + target.ColumnCount);
+                throw new ArgumentException(message, "target");
+            }
+
+            CopyToUnchecked(target, skipClearing);
+        }
+
+        internal virtual void CopyToUnchecked(MatrixStorage<T> target, bool skipClearing = false)
         {
             for (int j = 0; j < ColumnCount; j++)
             {
@@ -207,7 +227,7 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        public virtual void CopySubMatrixTo(MatrixStorage<T> target,
+        public void CopySubMatrixTo(MatrixStorage<T> target,
             int sourceRowIndex, int targetRowIndex, int rowCount,
             int sourceColumnIndex, int targetColumnIndex, int columnCount,
             bool skipClearing = false)
@@ -226,6 +246,15 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
                 sourceRowIndex, targetRowIndex, rowCount,
                 sourceColumnIndex, targetColumnIndex, columnCount);
 
+            CopySubMatrixToUnchecked(target, sourceRowIndex, targetRowIndex, rowCount,
+                sourceColumnIndex, targetColumnIndex, columnCount, skipClearing);
+        }
+
+        internal virtual void CopySubMatrixToUnchecked(MatrixStorage<T> target,
+            int sourceRowIndex, int targetRowIndex, int rowCount,
+            int sourceColumnIndex, int targetColumnIndex, int columnCount,
+            bool skipClearing = false)
+        {
             for (int j = sourceColumnIndex, jj = targetColumnIndex; j < sourceColumnIndex + columnCount; j++, jj++)
             {
                 for (int i = sourceRowIndex, ii = targetRowIndex; i < sourceRowIndex + rowCount; i++, ii++)
diff --git a/src/Numerics/LinearAlgebra/Storage/SparseCompressedRowMatrixStorage.cs b/src/Numerics/LinearAlgebra/Storage/SparseCompressedRowMatrixStorage.cs
index 50b77f7b..d0fa9599 100644
--- a/src/Numerics/LinearAlgebra/Storage/SparseCompressedRowMatrixStorage.cs
+++ b/src/Numerics/LinearAlgebra/Storage/SparseCompressedRowMatrixStorage.cs
@@ -338,20 +338,19 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             return hash;
         }
 
-        /// <remarks>Parameters assumed to be validated already.</remarks>
-        public override void CopyTo(MatrixStorage<T> target, bool skipClearing = false)
+        internal override void CopyToUnchecked(MatrixStorage<T> target, bool skipClearing = false)
         {
             var sparseTarget = target as SparseCompressedRowMatrixStorage<T>;
             if (sparseTarget != null)
             {
-                CopyTo(sparseTarget);
+                CopyToUnchecked(sparseTarget);
                 return;
             }
 
             var denseTarget = target as DenseColumnMajorMatrixStorage<T>;
             if (denseTarget != null)
             {
-                CopyTo(denseTarget, skipClearing);
+                CopyToUnchecked(denseTarget, skipClearing);
                 return;
             }
 
@@ -376,19 +375,8 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        void CopyTo(SparseCompressedRowMatrixStorage<T> target)
+        void CopyToUnchecked(SparseCompressedRowMatrixStorage<T> target)
         {
-            if (ReferenceEquals(this, target))
-            {
-                return;
-            }
-
-            if (RowCount != target.RowCount || ColumnCount != target.ColumnCount)
-            {
-                var message = string.Format(Resources.ArgumentMatrixDimensions2, RowCount + "x" + ColumnCount, target.RowCount + "x" + target.ColumnCount);
-                throw new ArgumentException(message, "target");
-            }
-
             target.ValueCount = ValueCount;
             target.Values = new T[ValueCount];
             target.ColumnIndices = new int[ValueCount];
@@ -401,14 +389,8 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        void CopyTo(DenseColumnMajorMatrixStorage<T> target, bool skipClearing)
+        void CopyToUnchecked(DenseColumnMajorMatrixStorage<T> target, bool skipClearing)
         {
-            if (RowCount != target.RowCount || ColumnCount != target.ColumnCount)
-            {
-                var message = string.Format(Resources.ArgumentMatrixDimensions2, RowCount + "x" + ColumnCount, target.RowCount + "x" + target.ColumnCount);
-                throw new ArgumentException(message, "target");
-            }
-
             if (!skipClearing)
             {
                 target.Clear();
@@ -428,7 +410,7 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        public override void CopySubMatrixTo(MatrixStorage<T> target,
+        internal override void CopySubMatrixToUnchecked(MatrixStorage<T> target,
             int sourceRowIndex, int targetRowIndex, int rowCount,
             int sourceColumnIndex, int targetColumnIndex, int columnCount,
             bool skipClearing = false)
@@ -441,7 +423,7 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             var sparseTarget = target as SparseCompressedRowMatrixStorage<T>;
             if (sparseTarget != null)
             {
-                CopySubMatrixTo(sparseTarget, 
+                CopySubMatrixToUnchecked(sparseTarget, 
                     sourceRowIndex, targetRowIndex, rowCount,
                     sourceColumnIndex, targetColumnIndex, columnCount,
                     skipClearing);
@@ -481,7 +463,7 @@ namespace MathNet.Numerics.LinearAlgebra.Storage
             }
         }
 
-        void CopySubMatrixTo(SparseCompressedRowMatrixStorage<T> target,
+        void CopySubMatrixToUnchecked(SparseCompressedRowMatrixStorage<T> target,
             int sourceRowIndex, int targetRowIndex, int rowCount,
             int sourceColumnIndex, int targetColumnIndex, int columnCount,
             bool skipClearing)