Did you ever get this to work? I'm in the same boat. I have a semi-transparent window over the whole screen, which I'm trying to draw at @ 30fps, but I can't seem to force the CALayer to update when I blit to the CVPixelBuffer. I will see the first couple frames, but then it stops updating. Observations: Strangely, the layer will update if I interact with another part of my app, like while dragging a slider in the preferences window. I can also force the layer to update by setting layer.contents = nil; layer.contents = buffer or I can use 2 buffers and continually set layer.contents to every other buffer, but this doesn't display smoothly. I just want something more efficient than setting an NSImageView 30x a second. Using [NSColor colorWithPatternImage:] works, but for the life of me I can't understand why this CVPixelBuffer isn't working, it's pretty simple stuff. Here's how I'm defining my CVPixelBuffer: NSDictionary *d = [NSDictionary dictionaryWithObjectsAndKeys: @{}, kCVPixelBufferIOSurfacePropertiesKey, @YES, kCVPixelBufferCGBitmapContextCompatibilityKey, @YES, kCVPixelBufferIOSurfaceCoreAnimationCompatibilityKey, nil]; CVPixelBufferRef _buffer; CVPixelBufferCreate(kCFAllocatorDefault, width, height, kCVPixelFormatType_32ARGB, (__bridge CFDictionaryRef)d, &_buffer); _overlay.contentView.layer.contents = (__bridge id _Nullable)(_buffer); I've also tried _overlay.contentView.layer.contents = (__bridge id _Nullable)CVPixelBufferGetIOSurface(_buffer);, but I get the same behavior. The code to update the CVPixelBuffer getting called at 30fps by an NSTimer (main thread): CVPixelBufferLockBaseAddress(_buffer, 0); void *rasterData = CVPixelBufferGetBaseAddress(_buffer); memcpy(rasterData, bitmapData, bytes); CVPixelBufferUnlockBaseAddress(_buffer, 0); None of these worked: [_overlay.contentView setLayerContentsRedrawPolicy:NSViewLayerContentsRedrawOnSetNeedsDisplay]; [_overlay.contentView.layer setNeedsDisplay]; [_overlay.contentView.layer display]; [_overlay.contentView display]; [_overlay.contentView setNeedsDisplay:YES];