How to extend your Mac's desktop to a TV or iPad

How to extend your Mac's desktop to a TV or iPad

1. Get started on your Mac

With Duet installed on both your Mac and your iOS device, open the Mac app. Duet's icon will appear in the menu bar, but it'll be dimmed. If you click it, you'll see a prompt to open the iOS app and run a USB cable between the devices.

How to extend your Mac's desktop to a TV or iPad

2. Extend the desktop

When you open the iOS app, your Mac's display will flicker momentarily, just like when you connect a display using Mini DisplayPort, Thunderbolt or HDMI. When the desktop reappears, it should immediately extend onto your iOS device.

How to extend your Mac's desktop to a TV or iPad

3. Pick a resolution

Click Duet's menu bar icon and put the pointer over your iPad in the list that appears. The top group of performance options set the iPad's desktop resolution, starting with a low quality that may work better for you with a low-spec MacBook.

How to extend your Mac's desktop to a TV or iPad

4. Low power options

If lowering the overall crispness of the extended desktop doesn't appeal, look at the third and fourth groups of options – frame rate and pixel quality – which contain settings that reduce the power that Duet demands from your Mac.

How to extend your Mac's desktop to a TV or iPad

5. Pick your GPU

On a MacBook Pro with two GPUs, click the cog in Duet's top-level menu. Under Preferences you can choose which is used, regardless of other apps' needs; the discrete one may boost performance, but it'll be at the expense of battery life.

How to extend your Mac's desktop to a TV or iPad

6. Absent visual effects

OS X's Reduce Transparency option kicks in while Duet is running. This is also to aid performance, and it should switch back when you quit Duet. You can force transparency on in the cog menu, but you may then see rendering glitches.