CIContext drawImage is very slow

Question

I am trying to draw a static CIImage using the CIContext drawImage in drawRect from GLKView, however I get about 4 frames per second. Suggestions for improvement?

// init code self.backgroundColor = UIColor.black; self.context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2]; CGColorSpaceRef cs = CGColorSpaceCreateDeviceRGB(); self.ciContext = [CIContext contextWithEAGLContext:self.context options:@{ kCIContextOutputColorSpace: (__bridge id)cs, kCIContextWorkingColorSpace: (__bridge id)cs }]; self.drawableColorFormat = GLKViewDrawableColorFormatRGBA8888; self.drawableDepthFormat = GLKViewDrawableDepthFormatNone; self.drawableMultisample = GLKViewDrawableMultisampleNone; self.drawableStencilFormat = GLKViewDrawableStencilFormatNone; // draw code - (void) drawRect:(CGRect)r { // Clears the screen to a black color glClearColor(0.0, 0.0, 0.0, 1.0); glClear(GL_COLOR_BUFFER_BIT); glEnable(GL_BLEND); glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA); [self.ciContext drawImage:self.ciImage inRect:self.bounds fromRect:self.bounds]; }