diff --git a/tests/nsl/sf_basic/NSLSFBasicTest.cpp b/tests/nsl/sf_basic/NSLSFBasicTest.cpp
index a63a72230..2e6cb9661 100644
--- a/tests/nsl/sf_basic/NSLSFBasicTest.cpp
+++ b/tests/nsl/sf_basic/NSLSFBasicTest.cpp
@@ -1,112 +1,112 @@
 /***************************************************************************
     File                 : NSLSFBasicTest.cpp
     Project              : LabPlot
     Description          : NSL Tests for basic special functions
     --------------------------------------------------------------------
     Copyright            : (C) 2019 Stefan Gerlach (stefan.gerlach@uni.kn)
  ***************************************************************************/
 
 /***************************************************************************
  *                                                                         *
  *  This program is free software; you can redistribute it and/or modify   *
  *  it under the terms of the GNU General Public License as published by   *
  *  the Free Software Foundation; either version 2 of the License, or      *
  *  (at your option) any later version.                                    *
  *                                                                         *
  *  This program is distributed in the hope that it will be useful,        *
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of         *
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the          *
  *  GNU General Public License for more details.                           *
  *                                                                         *
  *   You should have received a copy of the GNU General Public License     *
  *   along with this program; if not, write to the Free Software           *
  *   Foundation, Inc., 51 Franklin Street, Fifth Floor,                    *
  *   Boston, MA  02110-1301  USA                                           *
  *                                                                         *
  ***************************************************************************/
 
 #include "NSLSFBasicTest.h"
 
 extern "C" {
 #include "backend/nsl/nsl_sf_basic.h"
 }
 
 void NSLSFBasicTest::initTestCase() {
 	const QString currentDir = __FILE__;
 	m_dataDir = currentDir.left(currentDir.lastIndexOf(QDir::separator())) + QDir::separator() + QLatin1String("data") + QDir::separator();
 }
 
 //##############################################################################
 //#################  handling of empty and sparse files ########################
 //##############################################################################
 void NSLSFBasicTest::testlog2_int_C99() {
 	QBENCHMARK {
 		for (unsigned int i = 1; i < 1e7; i++)
 			Q_UNUSED((int)log2(i));
 	}
 }
 
 void NSLSFBasicTest::testlog2_int() {
-	for (unsigned int i = 1; i < 1e6; i++) {
+	for (unsigned int i = 1; i < 1e5; i++) {
 		int result = nsl_sf_log2_int(i);
 		QCOMPARE(result, (int)log2(i));
 	}
 
 	QBENCHMARK {
 		for (unsigned int i = 1; i < 1e7; i++)
 			nsl_sf_log2_int(i);
 	}
 }
 void NSLSFBasicTest::testlog2_longlong() {
 #ifndef _MSC_VER	/* not implemented yet */
-	for (unsigned long long i = 1; i < 1e6; i++) {
+	for (unsigned long long i = 1; i < 1e5; i++) {
 		int result = nsl_sf_log2_longlong(i);
 		QCOMPARE(result, (int)log2(i));
 	}
 
 	QBENCHMARK {
 		for (unsigned long long i = 1; i < 1e7; i++)
 			nsl_sf_log2_longlong(i);
 	}
 #endif
 }
 
 
 void NSLSFBasicTest::testlog2_int2() {
-	for (int i = 1; i < 1e6; i++) {
+	for (int i = 1; i < 1e5; i++) {
 		int result = nsl_sf_log2_int2(i);
 		QCOMPARE(result, (int)log2(i));
 	}
 
 	QBENCHMARK {
 		for (int i = 1; i < 1e7; i++)
 			nsl_sf_log2_int2(i);
 	}
 }
 
 void NSLSFBasicTest::testlog2_int3() {
-	for (unsigned int i = 1; i < 1e6; i++) {
+	for (unsigned int i = 1; i < 1e5; i++) {
 		int result = nsl_sf_log2_int3(i);
 		QCOMPARE(result, (int)log2(i));
 	}
 
 	QBENCHMARK {
 		for (unsigned int i = 1; i < 1e7; i++)
 			nsl_sf_log2_int3(i);
 	}
 }
 
 void NSLSFBasicTest::testlog2p1_int() {
-	for (int i = 1; i < 1e6; i++) {
+	for (int i = 1; i < 1e5; i++) {
 		int result = nsl_sf_log2p1_int(i);
 		QCOMPARE(result, (int)log2(i) + 1);
 	}
 
 	QBENCHMARK {
 		for (int i = 1; i < 1e7; i++)
 			nsl_sf_log2p1_int(i);
 	}
 
 }
 
 QTEST_MAIN(NSLSFBasicTest)