diff --git a/sdrgui/gui/glspectrum.cpp b/sdrgui/gui/glspectrum.cpp
index 642ba9329..44e80184f 100644
--- a/sdrgui/gui/glspectrum.cpp
+++ b/sdrgui/gui/glspectrum.cpp
@@ -812,7 +812,8 @@ void GLSpectrum::paintGL()
 			m_maxHold[i] = (j * m_powerRange) / 99.0 + m_referenceLevel;
 		}
 		{
-			GLfloat q3[2*m_fftSize];
+			//GLfloat q3[2*m_fftSize];
+		    GLfloat *q3 = m_shaderArrays.m_q3FFT;
 			Real bottom = -m_powerRange;
 
 			for(int i = 0; i < m_fftSize; i++) {
@@ -835,7 +836,8 @@ void GLSpectrum::paintGL()
 	{
 		{
 			Real bottom = -m_powerRange;
-			GLfloat q3[2*m_fftSize];
+			//GLfloat q3[2*m_fftSize];
+			GLfloat *q3 = m_shaderArrays.m_q3FFT;
 
 			for(int i = 0; i < m_fftSize; i++) {
 				Real v = (*m_currentSpectrum)[i] - m_referenceLevel;
@@ -860,7 +862,8 @@ void GLSpectrum::paintGL()
 		tickList = &m_timeScale.getTickList();
 
 		{
-			GLfloat q3[4*tickList->count()];
+			//GLfloat q3[4*tickList->count()];
+			GLfloat *q3 = m_shaderArrays.m_q3TickTime;
 			int effectiveTicks = 0;
 
 			for (int i= 0; i < tickList->count(); i++)
@@ -887,7 +890,8 @@ void GLSpectrum::paintGL()
 		tickList = &m_frequencyScale.getTickList();
 
 		{
-			GLfloat q3[4*tickList->count()];
+			//GLfloat q3[4*tickList->count()];
+			GLfloat *q3 = m_shaderArrays.m_q3TickFrequency;
 			int effectiveTicks = 0;
 
 			for (int i= 0; i < tickList->count(); i++)
@@ -920,7 +924,8 @@ void GLSpectrum::paintGL()
 		tickList = &m_powerScale.getTickList();
 
 		{
-			GLfloat q3[4*tickList->count()];
+			//GLfloat q3[4*tickList->count()];
+		    GLfloat *q3 = m_shaderArrays.m_q3TickPower;
 			int effectiveTicks = 0;
 
 			for(int i= 0; i < tickList->count(); i++)
@@ -947,7 +952,8 @@ void GLSpectrum::paintGL()
 		tickList = &m_frequencyScale.getTickList();
 
 		{
-			GLfloat q3[4*tickList->count()];
+			//GLfloat q3[4*tickList->count()];
+			GLfloat *q3 = m_shaderArrays.m_q3TickFrequency;
 			int effectiveTicks = 0;
 
 			for(int i= 0; i < tickList->count(); i++)
@@ -1572,6 +1578,8 @@ void GLSpectrum::applyChanges()
 		memset(m_histogram, 0x00, 100 * m_fftSize);
 		m_histogramHoldoff = new quint8[100 * m_fftSize];
 		memset(m_histogramHoldoff, 0x07, 100 * m_fftSize);
+
+		m_shaderArrays.allocFFT(2*m_fftSize);
 	}
 
 	if(fftSizeChanged || windowSizeChanged)
@@ -1579,6 +1587,10 @@ void GLSpectrum::applyChanges()
 		m_waterfallTextureHeight = waterfallHeight;
 		m_waterfallTexturePos = 0;
 	}
+
+	m_shaderArrays.allocTickTime(4*m_timeScale.getTickList().count());
+    m_shaderArrays.allocTickFrequency(4*m_frequencyScale.getTickList().count());
+    m_shaderArrays.allocTickPower(4*m_powerScale.getTickList().count());
 }
 
 void GLSpectrum::mouseMoveEvent(QMouseEvent* event)
diff --git a/sdrgui/gui/glspectrum.h b/sdrgui/gui/glspectrum.h
index 0dbae94a5..dcc4d8c65 100644
--- a/sdrgui/gui/glspectrum.h
+++ b/sdrgui/gui/glspectrum.h
@@ -72,6 +72,82 @@ public:
 	void connectTimer(const QTimer& timer);
 
 private:
+	struct ShaderArrays
+	{
+	    GLfloat *m_q3TickTime;
+	    GLfloat *m_q3TickFrequency;
+	    GLfloat *m_q3TickPower;
+	    GLfloat *m_q3FFT;
+
+	    uint32_t m_q3TickTimeSize;
+	    uint32_t m_q3TickTimeFrequencySize;
+	    uint32_t m_q3TickPowerSize;
+	    uint32_t m_q3FFTSize;
+
+	    ShaderArrays() :
+	        m_q3TickTime(0),
+	        m_q3TickFrequency(0),
+	        m_q3TickPower(0),
+	        m_q3FFT(0),
+	        m_q3TickTimeSize(0),
+	        m_q3TickTimeFrequencySize(0),
+	        m_q3TickPowerSize(0),
+	        m_q3FFTSize(0)
+	    {}
+
+	    ~ShaderArrays()
+	    {
+	        if (m_q3TickTime) { delete[] m_q3TickTime; }
+	        if (m_q3TickFrequency) { delete[] m_q3TickFrequency; }
+	        if (m_q3TickPower) { delete[] m_q3TickPower; }
+	        if (m_q3FFT) { delete[] m_q3FFT; }
+	    }
+
+	    void allocTickTime(uint32_t size)
+	    {
+	        if (size <= m_q3TickTimeSize) {
+	            return;
+	        }
+
+	        if (m_q3TickTime) { delete[] m_q3TickTime; }
+	        m_q3TickTime = new GLfloat[size];
+	        m_q3TickTimeSize = size;
+	    }
+
+        void allocTickFrequency(uint32_t size)
+        {
+            if (size <= m_q3TickTimeFrequencySize) {
+                return;
+            }
+
+            if (m_q3TickFrequency) { delete[] m_q3TickFrequency; }
+            m_q3TickFrequency = new GLfloat[size];
+            m_q3TickTimeFrequencySize = size;
+        }
+
+        void allocTickPower(uint32_t size)
+        {
+            if (size <= m_q3TickPowerSize) {
+                return;
+            }
+
+            if (m_q3TickPower) { delete[] m_q3TickPower; }
+            m_q3TickPower = new GLfloat[size];
+            m_q3TickPowerSize = size;
+        }
+
+        void allocFFT(uint32_t size)
+        {
+            if (size <= m_q3FFTSize) {
+                return;
+            }
+
+            if (m_q3FFT) { delete[] m_q3FFT; }
+            m_q3FFT = new GLfloat[size];
+            m_q3FFTSize = size;
+        }
+	};
+
 	struct ChannelMarkerState {
 		ChannelMarker* m_channelMarker;
 		QMatrix4x4 m_glMatrixWaterfall;
@@ -164,6 +240,7 @@ private:
 	GLShaderTextured m_glShaderHistogram;
 	int m_matrixLoc;
 	int m_colorLoc;
+	ShaderArrays m_shaderArrays;
 
 	static const int m_waterfallBufferHeight = 256;