diff --git a/libs/gtkmm2ext/nsglview.mm b/libs/gtkmm2ext/nsglview.mm
index 1008f5e602..ad0e7027fd 100644
--- a/libs/gtkmm2ext/nsglview.mm
+++ b/libs/gtkmm2ext/nsglview.mm
@@ -25,6 +25,9 @@
 
 #include <gdk/gdkquartz.h>
 
+//#define NSVIEW_PROFILE
+//#define DEBUG_NSVIEW_EXPOSURE
+
 #include <OpenGL/gl.h>
 #import  <Cocoa/Cocoa.h>
 
@@ -40,6 +43,7 @@
  * Gdk events propagate.
  */
 #ifndef ARDOUR_CANVAS_NSVIEW_TAG
+#error NO TAG
 #define ARDOUR_CANVAS_NSVIEW_TAG 0x0
 #endif
 
@@ -53,6 +57,8 @@ __attribute__ ((visibility ("hidden")))
 	Cairo::RefPtr<Cairo::ImageSurface> surf;
 	Gtkmm2ext::CairoCanvas *cairo_canvas;
 	NSInteger _tag;
+
+	GdkRectangle _expose_area;
 }
 
 @property (readwrite) NSInteger tag;
@@ -62,6 +68,7 @@ __attribute__ ((visibility ("hidden")))
 - (void) setCairoCanvas:(Gtkmm2ext::CairoCanvas*)c;
 - (void) reshape;
 - (void) setNeedsDisplayInRect:(NSRect)rect;
+- (void) setNeedsDisplay:(BOOL)yn;
 - (void) drawRect:(NSRect)rect;
 - (BOOL) canBecomeKeyWindow:(id)sender;
 - (BOOL) acceptsFirstResponder:(id)sender;
@@ -98,6 +105,7 @@ __attribute__ ((visibility ("hidden")))
 	_texture_id = 0;
 	_width = 0;
 	_height = 0;
+	_expose_area.x = _expose_area.y  = _expose_area.width = _expose_area.height = 0;
 
 	if (self) {
 		self.tag = ARDOUR_CANVAS_NSVIEW_TAG;
@@ -109,6 +117,13 @@ __attribute__ ((visibility ("hidden")))
 		glEnable (GL_TEXTURE_RECTANGLE_ARB);
 		[NSOpenGLContext clearCurrentContext];
 
+#if 1
+		[self setWantsBestResolutionOpenGLSurface:YES];
+		[self setWantsLayer:YES];
+#else
+		[self setWantsBestResolutionOpenGLSurface:NO];
+#endif
+
 		[self reshape];
 	}
 
@@ -138,6 +153,7 @@ __attribute__ ((visibility ("hidden")))
 
 - (void) reshape
 {
+	[super reshape];
 	[[self openGLContext] update];
 
 	NSRect bounds = [self bounds];
@@ -172,19 +188,54 @@ __attribute__ ((visibility ("hidden")))
 
 	_width  = width;
 	_height = height;
+
+	_expose_area.x = _expose_area.y = 0;
+	_expose_area.width = width;
+	_expose_area.height = height;
+}
+
+- (void) setNeedsDisplay:(BOOL)yn
+{
+	if (yn) {
+		_expose_area.x = _expose_area.y = 0;
+		_expose_area.width = _width;
+		_expose_area.height = _height;
+#ifdef DEBUG_NSVIEW_EXPOSURE
+		printf ("needsDisplay: FULL %d x %d\n", _width, _height);
+#endif
+	}
+	[super setNeedsDisplay:yn];
 }
 
 - (void) setNeedsDisplayInRect:(NSRect)rect
 {
-	[super setNeedsDisplayInRect:rect];
 #ifdef DEBUG_NSVIEW_EXPOSURE
 	printf ("needsDisplay: %5.1f %5.1f   %5.1f %5.1f\n",
 			rect.origin.x, rect.origin.y, rect.size.width, rect.size.height);
 #endif
+
+	//GdkRectangle r2 = {_expose_area.x, _expose_area.y, _expose_area.width, _expose_area.height };
+	if (_expose_area.width == 0 && _expose_area.height == 0) {
+		_expose_area.x = rect.origin.x;
+		_expose_area.y = rect.origin.y;
+		_expose_area.width = rect.size.width;
+		_expose_area.height = rect.size.height;
+	} else {
+		GdkRectangle r1 = {(int)rect.origin.x, (int)rect.origin.y, (int)rect.size.width, (int)rect.size.height};
+		gdk_rectangle_union (&r1, &_expose_area, &_expose_area);
+	}
+
+	GdkRectangle rw = {0, 0, _width, _height};
+	gdk_rectangle_intersect (&rw, &_expose_area, &_expose_area);
+
+	[super setNeedsDisplayInRect:rect];
 }
 
 - (void) drawRect:(NSRect)rect
 {
+#ifdef NSVIEW_PROFILE
+	const int64_t start = g_get_monotonic_time ();
+#endif
 	[[self openGLContext] makeCurrentContext];
 
 	glMatrixMode(GL_MODELVIEW);
@@ -194,10 +245,18 @@ __attribute__ ((visibility ("hidden")))
 	/* call back into CairoCanvas */
 	cairo_rectangle_t cairo_rect;
 
+#if 0
 	cairo_rect.x = rect.origin.x;
 	cairo_rect.y = rect.origin.y;
 	cairo_rect.width = rect.size.width;
 	cairo_rect.height = rect.size.height;
+#else
+	cairo_rect.x = _expose_area.x;
+	cairo_rect.y = _expose_area.y;
+	cairo_rect.width = _expose_area.width;
+	cairo_rect.height = _expose_area.height;
+#endif
+	_expose_area.x = _expose_area.y  = _expose_area.width = _expose_area.height = 0;
 
 	if (!surf || surf->get_width () != _width || surf->get_height() != _height) {
 		surf = Cairo::ImageSurface::create (Cairo::FORMAT_ARGB32, _width, _height);
@@ -271,6 +330,13 @@ __attribute__ ((visibility ("hidden")))
 	glSwapAPPLE();
 	[NSOpenGLContext clearCurrentContext];
 	[super setNeedsDisplay:NO];
+
+#ifdef NSVIEW_PROFILE
+	const int64_t end = g_get_monotonic_time ();
+	const int64_t elapsed = end - start;
+	printf ("NSGL::drawRect %f ms\n", elapsed / 1000.f);
+#endif
+
 }
 @end