Problems with SAOPass

Questions
1

Helo, i have problems to active SAOPass.

This is my code:

stats = new Stats();
renderPass = new THREE.RenderPass( scene, camera );
composer.addPass( renderPass );
saoPass = new THREE.SAOPass( scene, camera, true, true );
saoPass.params.output = parseInt( THREE.SAOPass.OUTPUT.Beauty );
saoPass.resolution.set(2048, 2048);
saoPass.renderToScreen = true;
saoPass.enabled = true;

			composer.addPass( saoPass );
			gui.addFolder('Oclusion Ambiental SAO')
			gui.add( saoPass.params, 'output', {
				'Beauty': THREE.SAOPass.OUTPUT.Beauty,
				'Beauty+SAO': THREE.SAOPass.OUTPUT.Default,
				'SAO': THREE.SAOPass.OUTPUT.SAO,
				'Depth': THREE.SAOPass.OUTPUT.Depth,
				'Normal': THREE.SAOPass.OUTPUT.Normal
			} ).onChange( function ( value ) {

				saoPass.params.output = parseInt( value );
				
				

			} );
		
			gui.add( saoPass.params, 'saoBias', - 1, 1 ).onChange(render);
			gui.add( saoPass.params, 'saoIntensity', 0, 1 ).onChange(render);
			gui.add( saoPass.params, 'saoScale', 0, 10 ).onChange(render);
			gui.add( saoPass.params, 'saoKernelRadius', 1, 100 ).onChange(render);
			gui.add( saoPass.params, 'saoMinResolution', 0, 1 ).onChange(render);
			gui.add( saoPass.params, 'saoBlur' ).onChange(render);
			gui.add( saoPass.params, 'saoBlurRadius', 0, 200 ).onChange(render);
			gui.add( saoPass.params, 'saoBlurStdDev', 0.5, 150 ).onChange(render);
			gui.add( saoPass.params, 'saoBlurDepthCutoff', 0.0, 0.1 ).onChange(render);		
			gui.open();

Then i have a render funtion:

function render(){
scene.background = background;
renderer.toneMappingExposure = params.exposure;
composer.render();
renderer.render( scene, camera );

}

With this code the SSAOPass not work. If i put the composer.render() in the animate function:

var animate = function () {requestAnimationFrame( animate );
stats.begin();
renderer.render( scene, camera );
composer.render();
stats.end();};
animate();

The code runs but the web goes very slow. Any idea?

Thanks.