diff --git a/src/test/java/org/apache/sysds/test/TestUtils.java b/src/test/java/org/apache/sysds/test/TestUtils.java
index 5958087..d5aea1c 100644
--- a/src/test/java/org/apache/sysds/test/TestUtils.java
+++ b/src/test/java/org/apache/sysds/test/TestUtils.java
@@ -45,6 +45,7 @@
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Random;
 import java.util.Set;
 import java.util.StringTokenizer;
@@ -885,7 +886,7 @@
 		String namesecond = name1;
 		boolean flag = true;
 		
-		/** to ensure that always the matrix with more nnz is iterated */
+		// to ensure that always the matrix with more nnz is iterated
 		if (m1.size() > m2.size()) {
 			first = m1;
 			second = m2;
@@ -896,28 +897,23 @@
 
 		int countErrorWithinTolerance = 0;
 		int countIdentical = 0;
-		double minerr = -1;
-		double maxerr = 0;
+		double minerr = Double.MAX_VALUE;
+		double maxerr = -Double.MAX_VALUE;
 
-		for (CellIndex index : first.keySet()) {
-			Double v1 = first.get(index);
-			Double v2 = second.get(index);
-			if (v1 == null)
-				v1 = 0.0;
-			if (v2 == null)
-				v2 = 0.0;
-			if (Math.abs(v1 - v2) < minerr || minerr == -1)
-				minerr = Math.abs(v1 - v2);
-			if (Math.abs(v1 - v2) > maxerr)
-				maxerr = Math.abs(v1 - v2);
+		for (Entry<CellIndex, Double> e : first.entrySet()) {
+			Double v1 = e.getValue() == null ? 0.0 : e.getValue();
+			Double v2 = second.get(e.getKey());
+			v2 = v2 == null ? 0.0 : v2;
+			minerr = Math.min(minerr, Math.abs(v1 - v2));
+			maxerr = Math.max(maxerr, Math.abs(v1 - v2));
 
-			if (!compareCellValue(first.get(index), second.get(index), 0, ignoreNaN)) {
-				if (!compareCellValue(first.get(index), second.get(index), tolerance, ignoreNaN)) {
+			if (!compareCellValue(v1, v2, 0, ignoreNaN)) {
+				if (!compareCellValue(v1, v2, tolerance, ignoreNaN)) {
 					countErrorWithinTolerance++;
 					if(!flag)
-						System.out.println(index+": "+first.get(index)+" <--> "+second.get(index));
+						System.out.println(e.getKey()+": "+v1+" <--> "+v2);
 					else 
-						System.out.println(index+": "+second.get(index)+" <--> "+first.get(index));
+						System.out.println(e.getKey()+": "+v2+" <--> "+v1);
 				}
 			} else {
 				countIdentical++;
@@ -962,7 +958,7 @@
 			case BOOLEAN: return ((Boolean)in1).compareTo((Boolean)in2);
 			case INT64:     return ((Long)in1).compareTo((Long)in2);
 			case FP64:  
-				return (Math.abs((Double)in1-(Double)in2) < tolerance)?0:	
+				return (Math.abs((Double)in1-(Double)in2) < tolerance)?0:
 					((Double)in1).compareTo((Double)in2);
 			default: throw new RuntimeException("Unsupported value type: "+vt);
 		}
diff --git a/src/test/java/org/apache/sysds/test/functions/append/AppendChainTest.java b/src/test/java/org/apache/sysds/test/functions/append/AppendChainTest.java
index d1b5f38..b85de58 100644
--- a/src/test/java/org/apache/sysds/test/functions/append/AppendChainTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/append/AppendChainTest.java
@@ -41,7 +41,7 @@
 	private final static int min=1;
 	private final static int max=100;
 	
-	private final static int rows = 1692;
+	private final static int rows = 492;
 	private final static int cols1 = 1059;
 	private final static int cols2a = 1;
 	private final static int cols3a = 1;
@@ -137,6 +137,7 @@
 	
 			int expectedCompiled = platform==ExecMode.SINGLE_NODE ?
 				0 : 8; //3x(rblk+chkpt), append, write
+			setOutputBuffering(false);
 			runTest(true, false, null, expectedCompiled);
 			runRScript(true);
 			
diff --git a/src/test/java/org/apache/sysds/test/functions/append/AppendMatrixTest.java b/src/test/java/org/apache/sysds/test/functions/append/AppendMatrixTest.java
index e20954c..9710262 100644
--- a/src/test/java/org/apache/sysds/test/functions/append/AppendMatrixTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/append/AppendMatrixTest.java
@@ -45,7 +45,7 @@
 	private final static int min=1;
 	private final static int max=100;
 	
-	private final static int rows = 1692;
+	private final static int rows = 492;
 	//usecase a: inblock single
 	private final static int cols1a = 375;
 	private final static int cols2a = 92;
@@ -179,6 +179,7 @@
 			
 			int expectedCompiled = platform==ExecMode.SINGLE_NODE ?
 				0 : 6; //2x(rblk+chkpt), append, write
+			setOutputBuffering(false);
 			runTest(true, false, null, expectedCompiled);
 			runRScript(true);
 			
diff --git a/src/test/java/org/apache/sysds/test/functions/append/AppendVectorTest.java b/src/test/java/org/apache/sysds/test/functions/append/AppendVectorTest.java
index 0bf3f23..014b73f 100644
--- a/src/test/java/org/apache/sysds/test/functions/append/AppendVectorTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/append/AppendVectorTest.java
@@ -107,6 +107,7 @@
 			
 			boolean exceptionExpected = false;
 			int numExpectedJobs = (platform == ExecMode.SINGLE_NODE) ? 0 : 6;
+			setOutputBuffering(false);
 			runTest(true, exceptionExpected, null, numExpectedJobs);
 			Assert.assertEquals("Wrong number of executed Spark jobs.",
 				numExpectedJobs, Statistics.getNoOfExecutedSPInst());
diff --git a/src/test/java/org/apache/sysds/test/functions/append/RBindCBindMatrixTest.java b/src/test/java/org/apache/sysds/test/functions/append/RBindCBindMatrixTest.java
index d161412..de5bd68 100644
--- a/src/test/java/org/apache/sysds/test/functions/append/RBindCBindMatrixTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/append/RBindCBindMatrixTest.java
@@ -128,12 +128,12 @@
 			rCmd = "Rscript" + " " + fullRScriptName + " " + inputDir() + " "+ expectedDir();
 			
 			double[][] A = getRandomMatrix(rows1, cols, min, max, sparsity, 823);
-	        writeInputMatrixWithMTD("A", A, true);
-	        double[][] B= getRandomMatrix(rows2, cols, min, max, sparsity, 923);
-	        writeInputMatrixWithMTD("B", B, true);
-	        
-	        //execute dml and r scripts
-	        runTest(true, false, null, -1);
+			writeInputMatrixWithMTD("A", A, true);
+			double[][] B= getRandomMatrix(rows2, cols, min, max, sparsity, 923);
+			writeInputMatrixWithMTD("B", B, true);
+
+			setOutputBuffering(false);
+			runTest(true, false, null, -1);
 			runRScript(true);
 	
 			//compare results
diff --git a/src/test/java/org/apache/sysds/test/functions/append/StringAppendTest.java b/src/test/java/org/apache/sysds/test/functions/append/StringAppendTest.java
index edacfad..ae2a602 100644
--- a/src/test/java/org/apache/sysds/test/functions/append/StringAppendTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/append/StringAppendTest.java
@@ -105,6 +105,7 @@
 			programArgs = new String[]{
 				"-args", Integer.toString(iters), output("C") };
 			
+			setOutputBuffering(false);
 			runTest(exceptionExpected ? DMLRuntimeException.class : null);
 		}
 		catch(Exception ex) {
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullDistributedMatrixMultiplicationTest.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullDistributedMatrixMultiplicationTest.java
index 9cedfe0..c2efbbc 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullDistributedMatrixMultiplicationTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullDistributedMatrixMultiplicationTest.java
@@ -45,7 +45,7 @@
 	private final static int rowsA = 1501;
 	private final static int colsA = 1103;
 	private final static int rowsB = 1103;
-	private final static int colsB = 923;
+	private final static int colsB = 323;
 	
 	private final static double sparsity1 = 0.7;
 	private final static double sparsity2 = 0.1;
@@ -192,6 +192,7 @@
 			double[][] B = getRandomMatrix(rowsB, colsB, 0, 1, sparsityB, 9873); 
 			writeInputMatrixWithMTD("B", B, true);
 	
+			setOutputBuffering(false);
 			runTest(true, false, null, -1); 
 			runRScript(true); 
 			
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullIntegerDivisionTest.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullIntegerDivisionTest.java
index cbfb317..2c57e75 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullIntegerDivisionTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullIntegerDivisionTest.java
@@ -47,7 +47,7 @@
 	private final static double eps = 1e-10;
 	
 	private final static int rows = 1100;
-	private final static int cols = 900;
+	private final static int cols = 300;
 	private final static double sparsity1 = 0.7;
 	private final static double sparsity2 = 0.1;
 	
@@ -264,7 +264,8 @@
 			}
 			boolean exceptionExpected = false;
 			runTest(true, exceptionExpected, null, -1); 
-			
+
+			setOutputBuffering(false);
 			runRScript(true); 
 		
 			//compare matrices 
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalMatrixTest.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalMatrixTest.java
index 2580c87..8ed852c 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalMatrixTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalMatrixTest.java
@@ -45,8 +45,8 @@
 	private final static String TEST_CLASS_DIR = TEST_DIR + FullLogicalMatrixTest.class.getSimpleName() + "/";
 	private final static double eps = 1e-10;
 
-	private final static int rows1 = 1383;
-	private final static int cols1 = 1432;
+	private final static int rows1 = 1183;
+	private final static int cols1 = 1032;
 
 	private final static double sparsity1 = 0.7;
 	private final static double sparsity2 = 0.01;
@@ -421,6 +421,7 @@
 			writeInputMatrixWithMTD("B", B, true);
 
 			//run tests
+			setOutputBuffering(false);
 			runTest(true, false, null, -1);
 			runRScript(true);
 
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalScalarLeftTest.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalScalarLeftTest.java
index e01967c..53ca27a 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalScalarLeftTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalScalarLeftTest.java
@@ -271,6 +271,7 @@
 			writeInputMatrixWithMTD("A", A, true);
 
 			//run tests
+			setOutputBuffering(false);
 			runTest(true, false, null, -1);
 			runRScript(true);
 
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalScalarRightTest.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalScalarRightTest.java
index 33bc263..b2fb7c5 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalScalarRightTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullLogicalScalarRightTest.java
@@ -269,6 +269,7 @@
 			writeInputMatrixWithMTD("A", A, true);
 
 			//run tests
+			setOutputBuffering(false);
 			runTest(true, false, null, -1);
 			runRScript(true);
 
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTest.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTest.java
index 052f5dd..997e43d 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTest.java
@@ -38,10 +38,10 @@
 	private final static String TEST_CLASS_DIR = TEST_DIR + FullMatrixMultiplicationTest.class.getSimpleName() + "/";
 	private final static double eps = 1e-10;
 	
-	private final static int rowsA = 1501;
-	private final static int colsA = 1703;
-	private final static int rowsB = 1703;
-	private final static int colsB = 1107;
+	private final static int rowsA = 1101;
+	private final static int colsA = 1203;
+	private final static int rowsB = 1203;
+	private final static int colsB = 1007;
 	
 	private final static double sparsity1 = 0.7;
 	private final static double sparsity2 = 0.1;
@@ -307,8 +307,8 @@
 			double[][] B = getRandomMatrix(rowsB, colsB, 0, 1, sparsityB, 3); 
 			writeInputMatrix("B", B, true);
 	
-			boolean exceptionExpected = false;
-			runTest(true, exceptionExpected, null, -1); 
+			setOutputBuffering(false);
+			runTest(true, false, null, -1); 
 			runRScript(true); 
 			
 			//compare matrices 
@@ -363,8 +363,8 @@
 			double[][] B = getRandomMatrix(rows2, cols2, 0, 1, sparsity1, 3); 
 			writeInputMatrix("B", B, true);
 	
-			boolean exceptionExpected = false;
-			runTest(true, exceptionExpected, null, -1); 
+			setOutputBuffering(false);
+			runTest(true, false, null, -1); 
 			runRScript(true); 
 			
 			//compare matrices 
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTransposeSelf2Test.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTransposeSelf2Test.java
index beb4b8a..7bb2991 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTransposeSelf2Test.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTransposeSelf2Test.java
@@ -162,6 +162,7 @@
 			writeInputMatrix("A", A, true);
 	
 			//run dml and R scripts
+			setOutputBuffering(false);
 			runTest(true, false, null, -1); 
 			runRScript(true); 
 			
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTransposeSelfTest.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTransposeSelfTest.java
index 9c497f2..b1e2358 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTransposeSelfTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationTransposeSelfTest.java
@@ -41,11 +41,11 @@
 	private final static double eps = 1e-10;
 	
 	//for CP
-	private final static int rows1 = 3500;
-	private final static int cols1 = 1500;
-	//for MR
-	private final static int rows2 = 7000;//7000;
-	private final static int cols2 = 750;//750; 
+	private final static int rows1 = 1100;
+	private final static int cols1 = 300;
+	//for Spark
+	private final static int rows2 = 2500;
+	private final static int cols2 = 750; 
 	
 	private final static double sparsity1 = 0.7;
 	private final static double sparsity2 = 0.1;
@@ -177,8 +177,8 @@
 			double[][] A = getRandomMatrix(rows, cols, 0, 1, sparsity, 7); 
 			writeInputMatrix("A", A, true);
 	
-			boolean exceptionExpected = false;
-			runTest(true, exceptionExpected, null, -1); 
+			setOutputBuffering(false);
+			runTest(true, false, null, -1); 
 			runRScript(true); 
 			
 			//compare matrices 
@@ -248,8 +248,8 @@
 			double[][] A = getRandomMatrix(rows, cols, 0, 1, sparsity, 7); 
 			writeInputMatrix("A", A, true);
 	
-			boolean exceptionExpected = false;
-			runTest(true, exceptionExpected, null, -1); 
+			setOutputBuffering(false);
+			runTest(true, false, null, -1); 
 			runRScript(true); 
 			
 			//compare matrices 
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationUltraSparseTest.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationUltraSparseTest.java
index b17ac20..c6e6934 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationUltraSparseTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMatrixMultiplicationUltraSparseTest.java
@@ -40,8 +40,8 @@
 	private final static double eps = 1e-10;
 	
 	private final static int rowsA = 1501;
-	private final static int colsA = 1703;
-	private final static int rowsB = 1703;
+	private final static int colsA = 1603;
+	private final static int rowsB = 1603;
 	private final static int colsB = 1107;
 	
 	private final static double sparsity1 = 0.7;
@@ -172,8 +172,8 @@
 			double[][] B = getRandomMatrix(rowsB, colsB, 0, 1, sparsityRight, 3); 
 			writeInputMatrix("B", B, true);
 	
-			boolean exceptionExpected = false;
-			runTest(true, exceptionExpected, null, -1); 
+			setOutputBuffering(false);
+			runTest(true, false, null, -1); 
 			runRScript(true); 
 			
 			//compare matrices 
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMinMaxComparisonTest.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMinMaxComparisonTest.java
index b593471..a9adc7a 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMinMaxComparisonTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullMinMaxComparisonTest.java
@@ -258,6 +258,7 @@
 			HDFSTool.writeMetaDataFile(input("B.mtd"), ValueType.FP64, mc2, FileFormat.TEXT);
 			
 			//run test
+			setOutputBuffering(false);
 			runTest(true, false, null, -1); 
 			runRScript(true); 
 			
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullPowerTest.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullPowerTest.java
index c1a76ea..dbce924 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullPowerTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/FullPowerTest.java
@@ -47,7 +47,7 @@
 	private final static double eps = 1e-10;
 	
 	private final static int rows = 1100;
-	private final static int cols = 900;
+	private final static int cols = 300;
 	private final static double sparsity1 = 0.7;
 	private final static double sparsity2 = 0.1;
 	
@@ -193,9 +193,8 @@
 				double[][] B = getRandomMatrix(1, 1, min, max, 1.0, 3);
 				writeScalarInputMatrixWithMTD( "B", B, true );
 			}
-			boolean exceptionExpected = false;
-			runTest(true, exceptionExpected, null, -1); 
-			
+			setOutputBuffering(false);
+			runTest(true, false, null, -1); 
 			runRScript(true); 
 		
 			//compare matrices 
diff --git a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/MatrixMultShortLhsTest.java b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/MatrixMultShortLhsTest.java
index 92d0d82..38c7645 100644
--- a/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/MatrixMultShortLhsTest.java
+++ b/src/test/java/org/apache/sysds/test/functions/binary/matrix_full_other/MatrixMultShortLhsTest.java
@@ -36,9 +36,9 @@
 	private final static double eps = 1e-10;
 	
 	private final static int rowsA = 10;
-	private final static int colsA = 2023;
-	private final static int rowsB = 2023;
-	private final static int colsB = 1997;
+	private final static int colsA = 1523;
+	private final static int rowsB = 1523;
+	private final static int colsB = 1397;
 	
 	private final static double sparsity1 = 0.9;
 	private final static double sparsity2 = 0.1;
@@ -91,6 +91,7 @@
 		writeInputMatrixWithMTD("B", B, true);
 
 		//run tests
+		setOutputBuffering(false);
 		runTest(true, false, null, -1); 
 		runRScript(true);